Analog modulated video transmission with variable symbol rate

ABSTRACT

A method of encoding video data comprising: generating coefficients based on digital sample values of the video data; determining a spectral efficiency for a channel; determining a value n based on the spectral efficiency of the channel; generating coefficient vectors, wherein each of the coefficient vectors includes n of the coefficients; determining an amplitude value for a coefficient vector based on a mapping pattern, wherein for each respective allowed coefficient vector in a plurality of allowed coefficient vectors: the mapping pattern maps the respective allowed coefficient vector to a respective amplitude value in a plurality of amplitude values, and the respective amplitude value is adjacent in an n-dimensional space to at least one other amplitude value in the plurality of amplitude values that is adjacent to the respective amplitude value in a monotonic number line of the amplitude values, and modulating an analog signal based on the amplitude values.

TECHNICAL FIELD

This disclosure relates to video encoding and decoding.

BACKGROUND

The ability to send and receive high-quality video data is one of thecompelling use-cases for deployment of advanced wireless networks, suchas Fifth Generation (5G) wireless networks. For example, 5G wirelessnetworks and beyond may enable streaming of high-quality video of liveevents, teleconferencing, and so on. In some instances, a user devicemay encode video data and then use a radio system to transmit theencoded video data to a wireless base station. The wireless basestation, in turn, may route the encoded video data through a network,such as the Internet, to a destination device.

Even with the high bandwidth capabilities of advanced wireless networks,devices may need to encode video data prior to transmission of the videodata. However, modern video coding standards may involve consumption ofconsiderable amounts of power, which may be in limited supply on mobiledevices, such as smartphones and tablets.

SUMMARY

This disclosure describes techniques for encoding and decoding videodata. As described herein, a video encoder may perform hybriddigital-analog modulation for transmission of video data. Whenperforming hybrid digital-analog modulation for transmission of videodata, the video encoder may transmit digital data and an analog signal.A video decoder uses both the digital data and analog signal toreconstruct the video data. The use of hybrid digital-analog modulationmay provide compression for the video data while potentially using lesspower or other resources than digital video codecs.

In one example, this disclosure describes a method of encoding videodata, the method comprising: generating coefficients based on the videodata; generating coefficient vectors, wherein each of the coefficientvectors includes n of the coefficients; for each of the coefficientvectors, determining an amplitude value for the coefficient vector basedon a mapping pattern, wherein for each respective allowed coefficientvector in a plurality of allowed coefficient vectors: the mappingpattern maps the respective allowed coefficient vector to a respectiveamplitude value in a plurality of amplitude values, and the respectiveamplitude value is adjacent in an n-dimensional space to at least oneother amplitude value in the plurality of amplitude values that isadjacent to the respective amplitude value in a monotonic number line ofthe amplitude values; modulating an analog signal based on the amplitudevalues for the coefficient vectors; and outputting the analog signal.

In another example, this disclosure describes a method of decoding videodata, the method comprising: determining, based on an analog signal,amplitude values for a plurality of coefficient vectors; for each of thecoefficient vectors, determining coefficients in the coefficient vectorbased on the amplitude value for the coefficient vector and a mappingpattern, wherein for each respective allowed coefficient vector in aplurality of allowed coefficient vectors: the mapping pattern maps therespective allowed coefficient vector to a respective amplitude value ina plurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerating the video data based on the coefficients in the coefficientvectors.

In another example, this disclosure describes a device for encodingvideo data, the device comprising: one or more processors implemented incircuitry, the one or more processors configured to: generatecoefficients based on video data; generate coefficient vectors, whereineach of the coefficient vectors includes n of the coefficients; and foreach of the coefficient vectors, determine an amplitude value for thecoefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; anda modem configured to modulate an analog signal based on the amplitudevalues for the coefficient vectors.

In another example, this disclosure describes a device for decodingvideo data, the device comprising: a modem configured to receive ananalog signal; and one or more processors implemented in circuitry, theone or more processors configured to: determine, based on the analogsignal, amplitude values for a plurality of coefficient vectors; foreach of the coefficient vectors, determine coefficients in thecoefficient vector based on the amplitude value for the coefficientvector and a mapping pattern, wherein for each respective allowedcoefficient vector in a plurality of allowed coefficient vectors: themapping pattern maps the respective allowed coefficient vector to arespective amplitude value in a plurality of amplitude values, and therespective amplitude value is adjacent in an n-dimensional space to atleast one other amplitude value in the plurality of amplitude valuesthat is adjacent to the respective amplitude value in a monotonic numberline of the amplitude values; and generate video data based on thecoefficients in the coefficient vectors.

In another example, this disclosure describes a device for encodingvideo data, the device comprising: means for generating coefficientsbased on video data; means for generating coefficient vectors, whereineach of the coefficient vectors includes n of the coefficients; for eachof the coefficient vectors, means for determining an amplitude value forthe coefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andmeans for modulating an analog signal based on the amplitude values forthe coefficient vectors.

In another example, this disclosure describes a device for decodingvideo data, the device comprising: means for determining, based on ananalog signal, amplitude values for a plurality of coefficient vectors;for each of the coefficient vectors, means for determining coefficientsin the coefficient vector based on the amplitude value for thecoefficient vector and a mapping pattern, wherein for each respectiveallowed coefficient vector in a plurality of allowed coefficientvectors: the mapping pattern maps the respective allowed coefficientvector to a respective amplitude value in a plurality of amplitudevalues, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andmeans for generating video data based on the coefficients in thecoefficient vectors.

In another example, this disclosure describes a computer-readable datastorage medium having instructions stored thereon that, when executed,cause one or more processors to: generate coefficients based on videodata; generate coefficient vectors, wherein each of the coefficientvectors includes n of the coefficients; for each of the coefficientvectors, determine an amplitude value for the coefficient vector basedon a mapping pattern, wherein for each respective allowed coefficientvector in a plurality of allowed coefficient vectors: the mappingpattern maps the respective allowed coefficient vector to a respectiveamplitude value in a plurality of amplitude values, and the respectiveamplitude value is adjacent in an n-dimensional space to at least oneother amplitude value in the plurality of amplitude values that isadjacent to the respective amplitude value in a monotonic number line ofthe amplitude values; and modulate an analog signal based on theamplitude values for the coefficient vectors.

In another example, this disclosure describes a computer-readable datastorage medium having instructions stored thereon that, when executed,cause one or more processors to: determine, based on an analog signal,amplitude values for a plurality of coefficient vectors; for each of thecoefficient vectors, determine coefficients in the coefficient vectorbased on the amplitude value for the coefficient vector and a mappingpattern, wherein for each respective allowed coefficient vector in aplurality of allowed coefficient vectors: the mapping pattern maps therespective allowed coefficient vector to a respective amplitude value ina plurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerate video data based on the coefficients in the coefficientvectors.

In another example, this disclosure describes a method of encoding videodata, the method comprising: generating coefficients based on digitalsample values of the video data; determining a spectral efficiency for achannel on which to send an analog signal; determining a value n basedon the spectral efficiency of the channel; generating coefficientvectors, wherein each of the coefficient vectors includes n of thecoefficients; for each of the coefficient vectors, determining anamplitude value for the coefficient vector based on a mapping pattern,wherein for each respective allowed coefficient vector in a plurality ofallowed coefficient vectors: the mapping pattern maps the respectiveallowed coefficient vector to a respective amplitude value in aplurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values, andmodulating the analog signal based on the amplitude values for thecoefficient vectors; and outputting the analog signal on the channel.

In another example, this disclosure describes a method of decoding videodata, the method comprising: receiving an analog signal that wastransmitted via a channel; demodulating the analog signal to determineamplitude values for a plurality of coefficient vectors; determining avalue n, wherein the value n is based on the spectral efficiency of thechannel; for each of the coefficient vectors, determining coefficientsin the coefficient vector based on the amplitude value for thecoefficient vector and a mapping pattern, wherein for each respectiveallowed coefficient vector in a plurality of allowed coefficientvectors: the mapping pattern maps the respective allowed coefficientvector to a respective amplitude value in a plurality of amplitudevalues, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerating the video data based on the coefficients in the coefficientvectors.

In another example, this disclosure describes a device for encodingvideo data, the device comprising: a memory configured to store thevideo data; one or more processors implemented in circuitry, the one ormore processors configured to: generate coefficients based on digitalsample values of the video data; determine a spectral efficiency for achannel on which to output an analog signal; determine a value n basedon the spectral efficiency of the channel; generate coefficient vectors,wherein each of the coefficient vectors includes n of the coefficients;for each of the coefficient vectors, determine an amplitude value forthe coefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values, andmodulate the analog signal based on the amplitude values for thecoefficient vectors; and a modem configured to output the analog signalon the channel.

In another example, this disclosure describes a device for decodingvideo data, the device comprising: a modem configured to receive ananalog signal that was transmitted via a channel; one or more processorsimplemented in circuitry, the one or more processors configured to:demodulate the analog signal to determine amplitude values for aplurality of coefficient vectors; determine a value n, wherein the valuen is based on the spectral efficiency of the channel; for each of thecoefficient vectors, determine coefficients in the coefficient vectorbased on the amplitude value for the coefficient vector and a mappingpattern, wherein for each respective allowed coefficient vector in aplurality of allowed coefficient vectors: the mapping pattern maps therespective allowed coefficient vector to a respective amplitude value ina plurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerate the video data based on the coefficients in the coefficientvectors.

In another example, this disclosure describes a device for encodingvideo data, the device comprising: means for generating coefficientsbased on digital sample values of the video data; means for determininga spectral efficiency for a channel on which to output an analog signal;means for determining a value n based on the spectral efficiency of thechannel; means for generating coefficient vectors, wherein each of thecoefficient vectors includes n of the coefficients; for each of thecoefficient vectors, means for determining an amplitude value for thecoefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values, andmeans for modulating the analog signal based on the amplitude values forthe coefficient vectors; and means for outputting the analog signal onthe channel.

In another example, this disclosure describes a device for decodingvideo data, the device comprising: means for receiving an analog signalthat was transmitted via a channel; means for demodulating the analogsignal to determine amplitude values for a plurality of coefficientvectors; means for determining a value n, wherein the value n is basedon the spectral efficiency of the channel; for each of the coefficientvectors, means for determining coefficients in the coefficient vectorbased on the amplitude value for the coefficient vector and a mappingpattern, wherein for each respective allowed coefficient vector in aplurality of allowed coefficient vectors: the mapping pattern maps therespective allowed coefficient vector to a respective amplitude value ina plurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andmeans for generating the video data based on the coefficients in thecoefficient vectors.

In another example, this disclosure describes a computer-readable datastorage medium having instructions stored thereon that, when executed,cause one or more processors to: generate coefficients based on digitalsample values of video data; determine a spectral efficiency for achannel on which to output an analog signal; determine a value n basedon the spectral efficiency of the channel; generate coefficient vectors,wherein each of the coefficient vectors includes n of the coefficients;for each of the coefficient vectors, determine an amplitude value forthe coefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values, andmodulate the analog signal based on the amplitude values for thecoefficient vectors; and output the analog signal on the channel.

In another example, this disclosure describes a computer-readable datastorage medium having instructions stored thereon that, when executed,cause one or more processors to: receive an analog signal that wastransmitted via a channel; demodulate the analog signal to determineamplitude values for a plurality of coefficient vectors; determine avalue n, wherein the value n is based on the spectral efficiency of thechannel; for each of the coefficient vectors, determine coefficients inthe coefficient vector based on the amplitude value for the coefficientvector and a mapping pattern, wherein for each respective allowedcoefficient vector in a plurality of allowed coefficient vectors: themapping pattern maps the respective allowed coefficient vector to arespective amplitude value in a plurality of amplitude values, and therespective amplitude value is adjacent in an n-dimensional space to atleast one other amplitude value in the plurality of amplitude valuesthat is adjacent to the respective amplitude value in a monotonic numberline of the amplitude values; and generate video data based on thecoefficients in the coefficient vectors.

In another example, this disclosure describes a method of encoding videodata, the method comprising: generating prediction data for the videodata; generating residual data based on the prediction data and digitalsample values of the video data; generating coefficients based on theresidual data; performing an interlacing process to generate aninterlaced amplitude value, wherein the interlacing process interlacesbits of two or more of the coefficients to generate the interlacedamplitude value; generating digital values based on the prediction data;and outputting one or more analog signals modulated based on theinterlaced amplitude value and the digital values.

In another example, this disclosure describes a method of decoding videodata, the method comprising: determining an interlaced amplitude valuebased on an analog signal; performing a deinterlacing process togenerate two or more coefficients, wherein bits of the two or morecoefficients are interlaced in the interlaced amplitude value;generating residual data based on the two or more coefficients;obtaining digital values; generating prediction data based on thedigital values; and reconstructing the video data based on theprediction data and the residual data.

In another example, this disclosure describes a device for encodingvideo data, the device comprising: a memory configured to store thevideo data, one or more processors implemented in circuitry, the one ormore processors configured to: generate prediction data for the videodata; generate residual data based on the prediction data and digitalsample values of the video data; generate coefficients based on theresidual data; perform an interlacing process to generate an interlacedamplitude value, wherein the interlacing process interlaces bits of twoor more of the coefficients to generate the interlaced amplitude value;and generate digital values based on the prediction data; and a modemconfigured to output one or more analog signals modulated based on theinterlaced amplitude value and the digital values.

In another example, this disclosure describes a device for decodingvideo data, the device comprising: a modem configured to obtain ananalog signal and digital values; and one or more processors implementedin circuitry, the one or more processors configured to: determine aninterlaced amplitude value based on an analog signal; perform adeinterlacing process to generate two or more coefficients, wherein bitsof the two or more coefficients are interlaced in the interlacedamplitude value; generate residual data based on the two or morecoefficients; obtain digital values; generate prediction data based onthe digital values; and reconstruct the video data based on theprediction data and the residual data.

In another example, this disclosure describes a device for encodingvideo data, the device comprising: means for generating prediction datafor the video data; means for generating residual data based on theprediction data and digital sample values of the video data; means forgenerating coefficients based on the residual data; means for performingan interlacing process to generate an interlaced amplitude value,wherein the interlacing process interlaces bits of two or more of thecoefficients to generate the interlaced amplitude value; and means formodulating an analog signal based on the interlaced amplitude value;means for generating digital values based on the prediction data; andmeans for outputting the analog signal and digital values based on theprediction block.

In another example, this disclosure describes a device for decodingvideo data, the device comprising: means for determining an interlacedamplitude value based on an analog signal; means for performing adeinterlacing process to generate two or more coefficients, wherein bitsof the two or more coefficients are interlaced in the interlacedamplitude value; means for generating residual data based on the two ormore coefficients; means for obtaining digital values; means forgenerating prediction data based on the digital values; and means forreconstructing the video data based on the prediction data and theresidual data.

In another example, this disclosure describes a computer-readable datastorage medium having instructions stored thereon that, when executed,cause one or more processors to: generate prediction data for videodata; generate residual data based on the prediction data and digitalsample values of the video data; generate coefficients based on theresidual data; perform an interlacing process to generate an interlacedamplitude value, wherein the interlacing process interlaces bits of twoor more of the coefficients to generate the interlaced amplitude value;and modulate an analog signal based on the interlaced amplitude value;generate digital values based on the prediction data; and output theanalog signal and digital values based on the prediction block.

In another example, this disclosure describes a computer-readable datastorage medium having instructions stored thereon that, when executed,cause one or more processors to: determine an interlaced amplitude valuebased on an analog signal; perform a deinterlacing process to generatetwo or more coefficients, wherein bits of the two or more coefficientsare interlaced in the interlaced amplitude value; generate residual databased on the two or more coefficients; obtain digital values; generateprediction data based on the digital values; and reconstruct video databased on the prediction data and the residual data.

The details of one or more examples are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description, drawings, and claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating an example encoding and decodingsystem that may perform the techniques of this disclosure.

FIG. 2 is a block diagram illustrating an example video encoder, inaccordance with one or more techniques of this disclosure.

FIG. 3 is a block diagram illustrating an example video decoder, inaccordance with one or more techniques of this disclosure.

FIG. 4 is a block diagram illustrating an example modem, in accordancewith one or more techniques of this disclosure.

FIG. 5 is an example constellation diagram for analog modulation in anI-Q domain.

FIG. 6 is a conceptual diagram illustrating received error during analogmodulation transmission.

FIG. 7 is a conceptual diagram illustrating an example of data signcoding in accordance with one or more techniques of this disclosure.

FIG. 8 is a conceptual diagram illustrating an example of minimum-valuecoding in accordance with one or more techniques of this disclosure.

FIG. 9 is a conceptual diagram illustrating an example mapping patternin accordance with one or more techniques of this disclosure.

FIG. 10 is a conceptual diagram illustrating amplitude valuescorresponding to the mapping pattern of FIG. 9, in accordance with oneor more techniques of this disclosure.

FIG. 11 is a conceptual diagram illustrating another example mappingpattern in accordance with one or more techniques of this disclosure.

FIG. 12 is a conceptual diagram illustrating amplitude valuescorresponding to the mapping pattern of FIG. 11, in accordance with oneor more techniques of this disclosure.

FIG. 13 is a conceptual diagram illustrating another example mappingpattern in accordance with one or more techniques of this disclosure.

FIG. 14 is a conceptual diagram illustrating amplitude valuescorresponding to the mapping pattern of FIG. 13, in accordance with oneor more techniques of this disclosure.

FIG. 15 is a conceptual diagram illustrating an example 3-dimensionalmapping pattern in accordance with one or more techniques of thisdisclosure.

FIG. 16 is a flowchart illustrating an example method for encoding videodata in accordance with one or more techniques of this disclosure.

FIG. 17 is a flowchart illustrating an example method for decoding videodata in accordance with one or more techniques of this disclosure.

FIG. 18 is a conceptual diagram illustrating a first example ofinterlacing, in accordance with one or more techniques of thisdisclosure.

FIG. 19 is a conceptual diagram illustrating a second example ofinterlacing, in accordance with one or more techniques of thisdisclosure.

FIG. 20 is a block diagram illustrating example effects of noise on acoding process.

FIG. 21 is a conceptual diagram illustrating gap ranges in accordancewith one or more techniques of this disclosure.

FIG. 22 is a flowchart illustrating an example method for encoding videodata in accordance with one or more techniques of this disclosure.

FIG. 23 is a flowchart illustrating an example method for decoding videodata in accordance with one or more techniques of this disclosure.

FIG. 24 is a block diagram illustrating an example analog compressionunit that uses a variable symbol rate, in accordance with one or moretechniques of this disclosure.

FIG. 25 is a flowchart illustrating an example method for encoding videodata in accordance with one or more techniques of this disclosure.

FIG. 26 is a flowchart illustrating an example method for decoding videodata in accordance with one or more techniques of this disclosure.

DETAILED DESCRIPTION

As mentioned above, the ability to send and receive high-quality videodata is one of the compelling use-cases for deployment of advancedwireless networks, such as Fifth Generation (5G) wireless networks.However, the use of state-of-the-art video codecs, such asH.264/Advanced Video Coding and H.265/High Efficiency Video Coding(HEVC), for encoding video data may be resource intensive and thereforeinvolve consumption of considerable amounts of power. This disclosuredescribes techniques for encoding video data that may be less resourceintensive.

This disclosure describes a hybrid digital-analog modulation system forcoding video data. As described herein, a video encoder may generatecoefficients based on video data. Additionally, the video encoder maygenerate coefficient vectors. Each of the coefficient vectors includes nof the coefficients. For each of the coefficient vectors, the videoencoder may determine an amplitude value for the coefficient vectorbased on a mapping pattern. The mapping pattern may map each allowedcoefficient vector to a unique amplitude value that is adjacent in ann-dimensional space to at least one other amplitude value that isadjacent to the unique amplitude value in a monotonic number line of theamplitude values (e.g., the number line of natural numbers, non-negativeintegers, integer values, etc.). The video encoder may modulate ananalog signal based on the amplitude values for the coefficient vectors.

A corresponding video decoder may perform analog amplitude demodulationand may determine, based on an analog signal, amplitude values for aplurality of coefficient vectors. For each of the coefficient vectors,the video decoder may determine coefficients in the coefficient vectorbased on the amplitude value for the coefficient vector and a mappingpattern. The mapping pattern may map each allowed coefficient vector toa unique amplitude value that is adjacent in n-dimensional space to atleast one other amplitude value that is adjacent to the unique amplitudevalue in a monotonic number line of the amplitude values. Each of thecoefficient vectors may include n of the coefficients. The video decodermay generate video data based on the coefficients in the coefficientvectors. The use of this mapping pattern may provide compression whensignaling data in the analog signal. Additionally, using analogamplitude modulation and demodulation may reduce power and resourceconsumption relative to video codecs like H.264/Advanced Video Codingand H.265/HEVC.

FIG. 1 is a block diagram illustrating an example video encoding anddecoding system 100 that may perform the techniques of this disclosure.The techniques of this disclosure are generally directed to coding(encoding and/or decoding) video data. In general, video data includesany data for processing a video. Thus, video data may include raw,unencoded video, encoded video, decoded (e.g., reconstructed) video, andvideo metadata, such as signaling data.

As shown in FIG. 1, system 100 includes a source device 102 thatprovides encoded video data to be decoded and displayed by a destinationdevice 116, in this example. In particular, source device 102 providesthe video data to destination device 116 via a computer-readable medium110. Source device 102 and destination device 116 may comprise any of awide range of devices, including desktop computers, notebook (i.e.,laptop) computers, tablet computers, set-top boxes, module device (e.g.,telephone handsets such as smartphones, tablet computers, etc.),televisions, cameras, display devices, digital media players, videogaming consoles, video streaming device, broadcast receiver devices,set-top boxes, or the like. In some cases, source device 102 anddestination device 116 may be equipped for wireless communication, andthus may be referred to as wireless communication devices.

In the example of FIG. 1, source device 102 includes video source 104,memory 106, video encoder 200, and modem 108. Destination device 116includes modem 122, video decoder 300, memory 120, and display device118. In accordance with this disclosure, video encoder 200 of sourcedevice 102 and video decoder 300 of destination device 116 may beconfigured to perform hybrid digital-analog modulation for videotransmission. Source device 102 represents an example of a videoencoding device, while destination device 116 represents an example of avideo decoding device. In other examples, a source device and adestination device may include other components or arrangements. Forexample, source device 102 may receive video data from an external videosource, such as an external camera. Likewise, destination device 116 mayinterface with an external display device, rather than include anintegrated display device.

System 100 as shown in FIG. 1 is merely one example. In general, anydigital video encoding and/or decoding device may perform the techniquesof this disclosure for hybrid digital-analog modulation for videotransmission. Source device 102 and destination device 116 are merelyexamples of such coding devices in which source device 102 generatesencoded video data for transmission to destination device 116. Thisdisclosure refers to a “coding” device as a device that performs coding(encoding and/or decoding) of data. Thus, video encoder 200 and videodecoder 300 represent examples of coding devices, in particular, a videoencoder and a video decoder, respectively. In some examples, sourcedevice 102 and destination device 116 may operate in a substantiallysymmetrical manner such that each of source device 102 and destinationdevice 116 includes video encoding and decoding components. Hence,system 100 may support one-way or two-way video transmission betweensource device 102 and destination device 116, e.g., for video streaming,video playback, video broadcasting, or video telephony.

In general, video source 104 represents a source of video data (i.e.,raw, unencoded video data) and provides a sequential series of pictures(also referred to as “frames”) of the video data to video encoder 200,which encodes data for the pictures. Video source 104 of source device102 may include a video capture device, such as a video camera, a videoarchive containing previously captured raw video, and/or a video feedinterface to receive video from a video content provider. As a furtheralternative, video source 104 may generate computer graphics-based dataas the source video, or a combination of live video, archived video, andcomputer-generated video. In each case, video encoder 200 encodes thecaptured, pre-captured, or computer-generated video data. Video encoder200 may rearrange the pictures from the received order (sometimesreferred to as “display order”) into a coding order for coding. Sourcedevice 102 may then output the encoded video data via modem 108 ontocomputer-readable medium 110 for reception and/or retrieval by, e.g.,modem 122 of destination device 116.

Memory 106 of source device 102 and memory 120 of destination device 116may represent general purpose memories. In some examples, memories 106,120 may store raw video data, e.g., raw video from video source 104 andraw, decoded video data from video decoder 300. Additionally oralternatively, memories 106, 120 may store software instructionsexecutable by, e.g., video encoder 200 and video decoder 300,respectively. Although memory 106 and memory 120 are shown separatelyfrom video encoder 200 and video decoder 300 in this example, it shouldbe understood that video encoder 200 and video decoder 300 may alsoinclude internal memories for functionally similar or equivalentpurposes. Furthermore, memories 106, 120 may store encoded video data,e.g., output from video encoder 200 and input to video decoder 300. Insome examples, portions of memories 106, 120 may be allocated as one ormore video buffers, e.g., to store raw, decoded, and/or encoded videodata.

Computer-readable medium 110 may represent any type of medium or devicecapable of transporting the encoded video data from source device 102 todestination device 116. In one example, computer-readable medium 110represents a communication medium to enable source device 102 totransmit encoded video data directly to destination device 116 inreal-time, e.g., via a radio frequency network or computer-basednetwork. Modem 108 may modulate a transmission signal including theencoded video data, and modem 122 may demodulate the receivedtransmission signal, according to a communication standard, such as awireless communication protocol. The communication medium may compriseany wireless or wired communication medium, such as a radio frequency(RF) spectrum or one or more physical transmission lines. For instance,the communication medium may include one or more 5G wirelesscommunication links. The communication medium may form part of apacket-based network, such as a local area network, a wide-area network,or a global network such as the Internet. The communication medium mayinclude routers, switches, base stations, or any other equipment thatmay be useful to facilitate communication from source device 102 todestination device 116.

In some examples, computer-readable medium 110 may include storagedevice 112. Source device 102 may output encoded data from modem 108 tostorage device 112. Similarly, destination device 116 may access encodeddata from storage device 112 via modem 122. Storage device 112 mayinclude any of a variety of distributed or locally accessed data storagemedia such as a hard drive, Blu-ray discs, DVDs, CD-ROMs, flash memory,volatile or non-volatile memory, or any other suitable digital storagemedia for storing encoded video data.

In some examples, computer-readable medium 110 may include file server114 or another intermediate storage device that may store the encodedvideo data generated by source device 102. Source device 102 may outputencoded video data to file server 114 or another intermediate storagedevice that may store the encoded video generated by source device 102.Destination device 116 may access stored video data from file server 114via streaming or download. File server 114 may be any type of serverdevice capable of storing encoded video data and transmitting thatencoded video data to the destination device 116. File server 114 mayrepresent a web server (e.g., for a website), a File Transfer Protocol(FTP) server, a content delivery network device, or a network attachedstorage (NAS) device. Destination device 116 may access encoded videodata from file server 114 through any standard data connection,including an Internet connection. This may include a wireless channel(e.g., a Wi-Fi connection), a wired connection (e.g., digital subscriberline (DSL), cable modem, etc.), or a combination of both that issuitable for accessing encoded video data stored on file server 114.File server 114 and modem 122 may be configured to operate according toa streaming transmission protocol, a download transmission protocol, ora combination thereof.

Modem 108 and modem 122 may represent wireless transmitters/receivers,modems, wired networking components (e.g., Ethernet cards), wirelesscommunication components that operate according to any of a variety ofIEEE 802.11 standards, or other physical components. In examples wheremodem 108 and modem 122 comprise wireless components, modem 108 andmodem 122 may be configured to transfer data, such as encoded videodata, according to a cellular communication standard, such as 4^(th)Generation (4G), 4G-LTE (Long-Term Evolution), LTE Advanced, 5G, or thelike. In some examples where modem 108 comprises a wireless transmitter,modem 108 and modem 122 may be configured to transfer data, such asencoded video data, according to other wireless standards, such as anIEEE 802.11 specification, an IEEE 802.15 specification (e.g., ZigBee™),a Bluetooth™ standard, or the like. In some examples, source device 102and/or destination device 116 may include respective system-on-a-chip(SoC) devices. For example, source device 102 may include an SoC deviceto perform the functionality attributed to video encoder 200 and/ormodem 108, and destination device 116 may include an SoC device toperform the functionality attributed to video decoder 300 and/or modem122.

The techniques of this disclosure may be applied to video coding insupport of any of a variety of multimedia applications, such asover-the-air television broadcasts, cable television transmissions,satellite television transmissions, Internet streaming videotransmissions, such as dynamic adaptive streaming over HTTP (DASH),digital video that is encoded onto a data storage medium, decoding ofdigital video stored on a data storage medium, or other applications.

Modem 122 of destination device 116 receives encoded video data fromcomputer-readable medium 110 (e.g., a communication medium, storagedevice 112, file server 114, or the like). The encoded video data mayinclude signaling information defined by video encoder 200, which isalso used by video decoder 300, such as syntax elements having valuesthat describe characteristics and/or processing of video blocks or othercoded units (e.g., slices, pictures, groups of pictures, sequences, orthe like). Display device 118 displays decoded pictures of the decodedvideo data to a user. Display device 118 may represent any of a varietyof display devices such as a liquid crystal display (LCD), a plasmadisplay, an organic light emitting diode (OLED) display, or another typeof display device.

Although not shown in FIG. 1, in some examples, video encoder 200 andvideo decoder 300 may each be integrated with an audio encoder and/oraudio decoder, and may include appropriate MUX-DEMUX units, or otherhardware and/or software, to handle multiplexed streams including bothaudio and video in a common data stream. If applicable, MUX-DEMUX unitsmay conform to the ITU H.223 multiplexer protocol, or other protocolssuch as the user datagram protocol (UDP).

Video encoder 200 and video decoder 300 each may be implemented as anyof a variety of suitable encoder and/or decoder circuitry, such as oneor more microprocessors, digital signal processors (DSPs), applicationspecific integrated circuits (ASICs), field programmable gate arrays(FPGAs), discrete logic, software, hardware, firmware or anycombinations thereof. When the techniques are implemented partially insoftware, a device may store instructions for the software in asuitable, non-transitory computer-readable medium and execute theinstructions in hardware using one or more processors to perform thetechniques of this disclosure. Each of video encoder 200 and videodecoder 300 may be included in one or more encoders or decoders, eitherof which may be integrated as part of a combined encoder/decoder (CODEC)in a respective device. A device including video encoder 200 and/orvideo decoder 300 may comprise an integrated circuit, a microprocessor,and/or a wireless communication device, such as a cellular telephone.

In general, video encoder 200 and video decoder 300 may code video datarepresented as arrays of digital sample values. Each digital samplevalue may be a value of color component in color coding format such asthe YUV (e.g., Y, Cb, Cr) format, red, green, and blue (RGB) format, HueSaturation Value (HSV) format, or other types of color format. In someexamples, video encoder 200 converts data formatted in a first colorformat to a second color format prior to encoding, and video decoder 300converts the data in the second color format to the first color format.Alternatively, pre- and post-processing units (not shown) may performthese conversions.

This disclosure may generally refer to coding (e.g., encoding anddecoding) of pictures to include the process of encoding or decodingdata of the picture. Similarly, this disclosure may refer to coding ofblocks of a picture to include the process of encoding or decoding datafor the blocks, e.g., prediction and/or residual coding.

In accordance with a technique of this disclosure, video encoder 200 mayuse hybrid digital-analog modulation to encode the video data. Asdescribed herein, video encoder 200 may generate coefficients based onvideo data. That is, video encoder 200 may generate coefficients basedon the arrays of digital sample values of the video data. In someexamples, as part of generating the coefficients, video encoder 200 maygenerate prediction data based on the video data (e.g., based on apicture of the video data). The prediction data may be an approximationof the video data (e.g., an approximation of a picture of the videodata) containing digital sample values. Video encoder 200 may quantizeand entropy encode the digital sample values. Modem 108 may transmit theentropy encoded digital sample values. Furthermore, as part ofgenerating the coefficients, video encoder 200 may generate residualdata based on the prediction data and the original video data. Forinstance, the residual data may include residual values indicatingdifferences between digital sample values of the prediction data andcorresponding digital sample values of the video data. Furthermore,video encoder 200 may apply a binarization process to convert theresidual values to coefficients. In some examples, video encoder 200 maythen quantize the coefficients.

Video encoder 200 may use the coefficients to generate coefficientvectors. Each of the coefficient vectors may include n of thecoefficients, where n is an integer value (e.g., an integer valuegreater than 1). In some examples, the coefficient vectors may consistof consecutive coefficients in a block of coefficients. In someexamples, video encoder 200 may determine the value of n based on aspectral efficiency of a channel.

For each of the coefficient vectors, video encoder 200 may determine anamplitude value for the coefficient vector based on a mapping pattern.The mapping pattern maps each allowed coefficient vector to a uniqueamplitude value a₁, where amplitude value a₁ is adjacent in ann-dimensional space to an amplitude value a₂, and amplitude value a₁ isadjacent to an amplitude value a₂ in a monotonic number line of theamplitude values. As described in greater detail below, example mappingpatterns may include an S-Snake mapping pattern, an M-Snake mappingpattern, an MS-Snake mapping pattern, and so on. In some examples,instead of determining amplitude values for coefficient vectors, videoencoder 200 may perform an interlacing process that generates amplitudevalues by interlacing bits of two or more coefficients.

Furthermore, video encoder 200 may modulate an analog signal based onthe amplitude values. For instance, video encoder 200 may convert a setof one or more amplitude values into an analog symbol. An analog symbolmay be a combination of a phase shift and a power (i.e., amplitude).Video encoder 200 may set a phase shift and power of a symbol samplinginstant of the analog signal based on the analog symbol.

Video decoder 300 may perform a decoding process that is generallyreciprocal to the encoding process performed by video encoder 200. Forinstance, video decoder 300 may determine amplitude values based on ananalog signal. In some examples, video decoder 300 may also obtainentropy-encoded digital sample values of prediction data. Video decoder300 may entropy decode and dequantize the entropy-encoded digital samplevalues to determine digital sample values of the prediction data. Insome examples, for each of the coefficient vectors, video decoder 300may determine coefficients in the coefficient vector based on theamplitude value for the coefficient vector and a mapping pattern. Themapping pattern used by video decoder 300 may be the same as the mappingpattern used by video encoder 200. Thus, the mapping pattern may mapeach allowed coefficient vector to a unique amplitude value that isadjacent in an n-dimensional space to at least one other amplitude valuethat is adjacent to the unique amplitude value in a monotonic numberline of the amplitude values. Each of the coefficient vectors includes nof the coefficients. In some examples, the value n may be determinedbased on a spectral efficiency of a channel. Furthermore, in someexamples, instead of using the mapping pattern, video decoder 300 mayperform a deinterlacing process that deinterlaces bits of two or morecoefficients from an amplitude value.

Furthermore, video decoder 300 may generate video data based on thecoefficients in the coefficient vectors. For instance, video decoder 300may dequantize the coefficients in the coefficient vectors and apply ade-binarization process to the dequantized coefficients to generatedigital sample values. Video decoder 300 may reconstruct the video databased on the digital sample values generated from the coefficients andthe digital sample values of the prediction block. For instance, videodecoder 300 may add digital sample values generated from thecoefficients to corresponding digital sample values of the predictionblock to generate the video data. Encoding and decoding video data inthis way may provide compression of the video data while not using asmany computational resources as other video codecs, such as H.264/AVCand H.265/HEVC.

FIG. 2 is a block diagram illustrating an example video encoder 200, inaccordance with one or more techniques of this disclosure. FIG. 2 isprovided for purposes of explanation and should not be consideredlimiting of the techniques as broadly exemplified and described in thisdisclosure. In the example of FIG. 2, video encoder 200 includes videodata memory 202, a prediction unit 204, a quantization unit 206, anentropy encoding unit 208, a buffer 210, a residual generation unit 212,and an analog compression unit 214. In the example of FIG. 2, analogcompression unit 214 includes a binarization unit 216, a quantizationunit 218, a packing unit 220, and an analog modulation unit 222. Any orall of video data memory 202, prediction unit 204, quantization unit206, entropy encoding unit 208, buffer 210, residual generation unit212, and analog compression unit 214 (including binarization unit 216,quantization unit 218, packing unit 220, and analog modulation unit 222)may be implemented in one or more processors or in processing circuitry.For instance, the units of video encoder 200 may be implemented as oneor more circuits or logic elements as part of hardware circuitry, or aspart of a processor, ASIC, or FPGA. Moreover, video encoder 200 mayinclude additional or alternative processors or processing circuitry toperform these and other functions.

Video data memory 202 may store video data to be encoded by thecomponents of video encoder 200. Video encoder 200 may receive the videodata stored in video data memory 202 from, for example, video source 104(FIG. 1). Video data memory 202 and buffer 210 may be formed by any of avariety of memory devices, such as dynamic random access memory (DRAM),including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM),resistive RAM (RRAM), or other types of memory devices. Video datamemory 202 and buffer 210 may be provided by the same memory device orseparate memory devices. In various examples, video data memory 202 maybe on-chip with other components of video encoder 200, as illustrated,or off-chip relative to those components.

In this disclosure, references to video data memory 202 should not beinterpreted as being limited to memory internal to video encoder 200,unless specifically described as such, or memory external to videoencoder 200, unless specifically described as such. Rather, reference tovideo data memory 202 should be understood as reference memory thatstores video data that video encoder 200 receives for encoding (e.g.,video data for a current block that is to be encoded). Memory 106 ofFIG. 1 may also provide temporary storage of outputs from the variousunits of video encoder 200.

The various units of FIG. 2 are illustrated to assist with understandingthe operations performed by video encoder 200. The units may beimplemented as fixed-function circuits, programmable circuits, or acombination thereof. Fixed-function circuits refer to circuits thatprovide particular functionality and are preset on the operations thatcan be performed. Programmable circuits refer to circuits that can beprogrammed to perform various tasks and provide flexible functionalityin the operations that can be performed. For instance, programmablecircuits may execute software or firmware that cause the programmablecircuits to operate in the manner defined by instructions of thesoftware or firmware. Fixed-function circuits may execute softwareinstructions (e.g., to receive parameters or output parameters), but thetypes of operations that the fixed-function circuits perform aregenerally immutable. In some examples, one or more of the units may bedistinct circuit blocks (fixed-function or programmable), and in someexamples, one or more of the units may be integrated circuits.

Video encoder 200 may include arithmetic logic units (ALUs), elementaryfunction units (EFUs), digital circuits, analog circuits, and/orprogrammable cores, formed from programmable circuits. In examples wherethe operations of video encoder 200 are performed using softwareexecuted by the programmable circuits, memory 106 (FIG. 1) may store theinstructions (e.g., object code) of the software that video encoder 200receives and executes, or another memory within video encoder 200 (notshown) may store such instructions. Video data memory 202 is configuredto store received video data.

In the example of FIG. 2, video data memory 202 may receive and storevideo data. Prediction unit 204 may generate prediction data based onthe video data. The prediction data include digital sample values. Insome examples, the prediction data may be a coarse image description,which may also be referred to as an “image approximation.” The coarseimage description may typically be transmitted with data packets havingsmall sizes. Video decoder 300 may use the data in such data packets toreconstruct a low-resolution image. Modem 108 may transmit the datapackets using a regular 5G digital data multiplexing and channel codingscheme or another digital data multiplexing and channel coding scheme.

Prediction unit 204 may generate the prediction data in one of variousways. For instance, in some examples, prediction unit 204 may generatedigital sample values of the prediction data by determining, for each2-dimensional group (i.e., block) of digital sample values in a pictureof the original video data, an average of the digital sample values inthe block. For purposes of determining residual data, residualgeneration unit 212 may assume that each sample value in the block isequal to the average. However, only the average for the block is passedon to quantization unit 206. In another example, prediction unit 204 maygenerate the prediction data by determining a digital sample value of atop-left or center pixel of each block in a picture and discarding theremaining sample values. For purposes of determining residual data,residual generation unit 212 may assume that each sample value in theblock is equal to the determined digital sample value. However, only thedetermined sample value is passed on to quantization unit 206. Thus, thenumber of digital sample values passed on to quantization unit 206 maybe significantly less than the number of digital sample values in thepicture.

Quantization unit 206 may apply a quantization process to generatequantized digital sample values based on the prediction data generatedby prediction unit 204. Quantization generally refers to a process inwhich the digital sample values, such as the digital sample values inthe prediction data, are quantized to possibly reduce the amount of dataused to represent the digital sample values, providing furthercompression. By performing the quantization process, quantization unit206 may reduce the bit depth associated with some or all of the digitalsample values. For example, quantization unit 206 may round an n-bitdigital sample value down to an m-bit digital sample value duringquantization, where n is greater than m. In some examples, to performquantization, quantization unit 206 may perform a bitwise right-shift ofthe value to be quantized.

Entropy encoding unit 208 may then perform entropy encoding on thequantized digital sample values. For example, entropy encoding unit 208may perform various types of entropy encoding processes, such as aContact Adaptive Binary Arithmetic Coding (CABAC) encoding process, acontext-adaptive variable length coding (CAVLC) process, avariable-to-variable (V2V) length encoding process, a syntax-basedcontext-adaptive binary arithmetic coding (SBAC) process, a ProbabilityInterval Partitioning Entropy (PIPE) encoding process, anExponential-Golomb encoding process, or another type of entropy encodingprocess. Buffer 210 may store the entropy-encoded quantized digitalsample values.

Furthermore, in the example of FIG. 2, residual generation unit 212generates residual data based on the digital sample values of theprediction data and digital sample values of the original video data.For example, residual generation unit 212 may subtract digital samplevalues of the prediction data from corresponding digital sample valuesof the original video data to generate the residual data.

Analog compression unit 214 modulates an analog signal based on theresidual data. In the example of FIG. 2, binarization unit 216 of analogcompression unit 214 converts the residual data into coefficients. Thecoefficients may be binary values. In some examples, binarization unit216 applies a transform to the residual data to generate thecoefficients. For instance, in one example, binarization unit 216 mayapply a transform (e.g., a Discrete Cosine Transform (DCT), a DiscreteSine Transform (DST), or other type of transform) to the residual datato generate the coefficients.

Quantization unit 218 of analog compression unit 214 may apply aquantization process to the coefficients. The quantization process mayreduce the number of bits used to represent the coefficients. In someexamples, quantization unit 218 may perform the quantization process byright shifting binary representations of the coefficients by a specificnumber of positions. In other examples, the coefficients may begenerated in other ways. For example, video encoder 200 may generate thecoefficients without applying the quantization process.

In accordance with some examples of this disclosure, packing unit 220 ofanalog compression unit 214 generates coefficient vectors. Each of thecoefficient vectors includes n of the coefficients. For each of thecoefficient vectors, packing unit 220 determines an amplitude value forthe coefficient vector based on a mapping pattern. As described ingreater detail elsewhere in this disclosure, an amplitude value mayindicate an amplitude of an in-phase (I) component or a quadrature (Q)component in an I-Q domain. As described in greater detail elsewhere inthis disclosure, the mapping pattern may map each allowed coefficientvector to a unique amplitude value that is adjacent in an n-dimensionalspace to at least one other amplitude value that is adjacent to theunique amplitude value in a monotonic number line of the amplitudevalues. The monotonic number line is a sequence of numbers that alwaysincreases or always decreases. Numbers in the number line may or may notbe equally separated. The allowed coefficient vectors include any vectorof n coefficients, where each coefficient within the vector is limitedto a predefined allowable set of values for that coefficient. In someexamples, packing unit 220 determines n based on a spectral efficiencyof a channel. In some examples, packing unit 220 performs an interlacingprocess that interlaces the bits of two or more of the coefficients toform an amplitude value.

Analog modulation unit 222 may modulate an analog signal based on theamplitude values. In some examples, as part of modulating the analogsignal, analog modulation unit 222 may determine analog symbols based onone or more of the amplitude values. In some examples, the analogsymbols are continuous, e.g., the analog symbols are not quantized toany quadrature amplitude modulation (QAM) level as is common intraditional digital transmission. Using analog modulation, as opposed tostandard modulation techniques, might not require retransmission. Forinstance, errors occurring when transmitting modulated digital data maybe detected (e.g., using checksums) and a receiver may requestretransmission of the digital data. However, minor changes in phaseshift and power during transmission of analog modulated data may notrequire retransmission because small changes in phase or power in theanalog modulated data are unlikely to introduce large amounts ofdistortion in the reconstructed video data. Thus, the use of analogmodulation may reduce complexity, reduce latency, and may reduce powerconsumption. Modem 108 may transmit the analog symbols.

In some examples, analog modulation unit 222 may generate pairs ofamplitude values (i.e., amplitude value pairs) to generate an analogsymbol. The amplitude values in an amplitude value pair may beconsecutive amplitude values generated by packing unit 220. As describedbelow with respect to FIG. 5 and FIG. 6, analog modulation unit 222 maydetermine a point in an I-Q plane that corresponds to the analog symbol.One amplitude value in the amplitude value pair may correspond to an Icomponent of the point and the other amplitude value in the amplitudevalue pair may correspond to the Q component of the point. Analogmodulation unit 222 may determine, based on the determined point, aphase shift and power for a symbol sampling instant in an analog signalthat modem 108 transmits to destination device 116.

FIG. 3 is a block diagram illustrating an example video decoder 300, inaccordance with one or more techniques of this disclosure. FIG. 3 isprovided for purposes of explanation and is not limiting on thetechniques as broadly exemplified and described in this disclosure. Inthe example of FIG. 3, video decoder 300 includes a buffer 302, anentropy decoding unit 304, a dequantization unit 306, an analogdecompression unit 308, a reconstruction unit 310, and a video datamemory 312. In the example of FIG. 3, analog decompression unit 308includes an analog demodularization unit 314, an unpacking unit 316, adequantization unit 318, and a de-binarization unit 320. Any or all ofentropy decoding unit 304, dequantization unit 306, analog decompressionunit 308 (including analog demodularization unit 314, unpacking unit316, dequantization unit 318, and de-binarization unit 320), andreconstruction unit 310 may be implemented in one or more processors orin processing circuitry. For instance, the units of video decoder 300may be implemented as one or more circuits or logic elements as part ofhardware circuitry, or as part of a processor, ASIC, of FPGA. Moreover,video decoder 300 may include additional or alternative processors orprocessing circuitry to perform these and other functions.

Buffer 302 may store digital video data to be decoded by the componentsof video decoder 300. The digital video data stored in buffer 302 may beobtained, for example, from modem 122 or a storage medium. Video datamemory 312 generally stores decoded pictures, which video decoder 300may output. Buffer 302 and video data memory 312 may be formed by any ofa variety of memory devices, such as DRAM, including SDRAM, MRAM, RRAM,or other types of memory devices. Buffer 302 and video data memory 312may be provided by the same memory device or separate memory devices. Invarious examples, buffer 302 and video data memory 312 may be on-chipwith other components of video decoder 300, or off-chip relative tothose components.

The various units shown in FIG. 3 are illustrated to assist withunderstanding the operations performed by video decoder 300. The unitsmay be implemented as fixed-function circuits, programmable circuits, ora combination thereof. Similar to FIG. 2, fixed-function circuits referto circuits that provide particular functionality, and are preset on theoperations that can be performed. Programmable circuits refer tocircuits that can be programmed to perform various tasks and provideflexible functionality in the operations that can be performed. Forinstance, programmable circuits may execute software or firmware thatcause the programmable circuits to operate in the manner defined byinstructions of the software or firmware. Fixed-function circuits mayexecute software instructions (e.g., to receive parameters or outputparameters), but the types of operations that the fixed-functioncircuits perform are generally immutable. In some examples, one or moreof the units may be distinct circuit blocks (fixed-function orprogrammable), and in some examples, one or more of the units may beintegrated circuits.

Video decoder 300 may include ALUs, EFUs, digital circuits, analogcircuits, and/or programmable cores formed from programmable circuits.In examples where the operations of video decoder 300 are performed bysoftware executing on the programmable circuits, on-chip or off-chipmemory may store instructions (e.g., object code) of the software thatvideo decoder 300 receives and executes.

In the example of FIG. 3, modem 122 may receive entropy-encoded digitalsample values. Buffer 302 may store the entropy-encoded digital samplevalues received by modem 122. Entropy decoding unit 304 may perform aprocess to entropy decode the entropy-encoded digital sample values inbuffer 302. Entropy decoding unit 304 may perform various types ofentropy decoding processes, such as a CABAC decoding process, a CAVLCdecoding process, a V2V length decoding process, a SBAC decodingprocess, a PIPE decoding process, an Exponential-Golomb decodingprocess, or another type of entropy decoding process. Dequantizationunit 306 may dequantize the digital sample values.

Analog demodulation unit 314 of analog decompression unit 308 may obtainan analog signal from modem 122. Analog demodulation unit 314 may thendetermine a phase shift and power of the analog signal for a symbolsampling instant. Analog demodulation unit 314 may then determine apoint in an I-Q plane that corresponds to the phase shift and power forthe symbol sampling instant. Analog demodulation unit 314 may thendetermine a pair of amplitude values corresponding to the determinedpoint. Specifically, analog demodulation unit 314 may set a firstamplitude value of the amplitude value pair to an I component of thepoint and may set a second amplitude value of the amplitude value pairto a Q component of the point.

For each coefficient vector (and therefore for each amplitude valuedetermined by analog demodulation unit 314), unpacking unit 316 maydetermine coefficients in the coefficient vector based on the amplitudevalue for the coefficient vector and a mapping pattern. The mappingpattern may map each allowed coefficient vector to a unique amplitudevalue that is adjacent in an n-dimensional space to at least one otheramplitude value that is adjacent to the unique amplitude value in amonotonic number line of the amplitude values. Each of the coefficientvectors includes n of the coefficients. The allowed coefficient vectorsinclude any vector of n coefficients, where each coefficient within thevector is limited to a predefined allowable range for that coefficient.In other examples, unpacking unit 316 may perform a deinterlacingprocess that deinterlaces the bits of two or more coefficients from bitsof the amplitude value.

Dequantization unit 318 of analog decompression unit 308 may dequantizethe coefficients of the coefficient vectors. For example, dequantizationunit 318 may left-shift binary values representing the coefficients.De-binarization unit 320 of analog decompression unit 308 may thenconvert the coefficients into digital sample values. For example,de-binarization unit 320 may apply an inverse transform (e.g., aninverse DCT, an inverse DST, etc.) to the coefficients to convert thecoefficients into digital sample values. Reconstruction unit 310 mayreconstruct digital sample values of a picture of the video data basedon the digital sample values generated by analog decompression unit 308and the digital sample values generated by dequantization unit 306. Asdescribed above, the prediction data generated by prediction unit 204may include a single digital sample value for each block of a picture.Reconstruction unit 310 may determine digital sample values for eachsample location of the block. For instance, reconstruction unit 310 mayset the digital sample value of each sample location of the block equalto the digital sample value for the block included in the predictiondata. In some examples, reconstruction unit 310 may interpolate digitalsample values for the block based on the transmitted digital samplevalue for the block and the transmitted digital sample values for one ormore neighboring blocks. Reconstruction unit 310 may reconstruct digitalsample values of the picture based on the digital sample valuesgenerated by analog decompression unit 308 and the determined digitalsample values for the locations within each of the blocks of thepicture. For instance, reconstruction unit 310 may add digital samplevalues generated by analog decompression unit 308 to correspondingdigital sample values for locations within the blocks of the picture.Video data memory 312 may store the reconstructed digital sample values,e.g., for subsequent output and display.

FIG. 4 is a block diagram illustrating an example modem 400, inaccordance with one or more techniques of this disclosure. Modem 400 maybe an instance of modem 108 of source device 102 or modem 122 ofdestination device 116. In the example of FIG. 4, modem 400 includes aTrBk cyclic redundancy check (CRC) attachment unit 402, a code blocksegmentation unit 404, a channel coding unit 406, a rate matching unit408, a code block concatenation unit 410, a scrambler unit 412, amodulation unit 414, a resource mapper 416, and an OrthogonalFrequency-Division Multiplexing (OFDM) signal generation unit 418. Inother examples, other types of modems may include other components. TrBkCRC attachment unit 402 may receive the entropy-encoded digital samplevalues from buffer 210 of video encoder 200. Resource mapper 416 mayreceive the analog symbols generated by analog modulation unit 222.

TrBk CRC attachment unit 402 calculates CRC bits for a payload. Thepayload may include digital values generated by video encoder 200 (e.g.,entropy-encoded data generated by entropy encoding unit 208, shiftvalues, interlacing process information, quantization information, dataindicating numbers of coefficients in coefficient vectors, and/or otherinformation). Code block segmentation unit 404 may segment a payloadinto code blocks, where a code block is the maximal payload size that achannel decoder (e.g., low-density parity-check code (LDPC) for 5G datachannel or Turbo code for 4G data) is allowed to encode. Channel codingunit 406 implements a channel coder that adds redundancy to cope withchannel error (e.g., LDPC for 5G data and Turbo code for 4G data). Ratematching unit 408 selects the number of bits to be transmitted accordingto the data size allocation, per code block. Code block concatenationunit 410 may concatenate the selected bits of all the code blocks.Scrambler unit 412 may generate scrambled bits by applying anexclusive-or (XOR) operation to XOR the concatenated data with a pseudorandom gold sequence that is unique per user. Modulation unit 414 maymodulate the scrambled bits according to a modulation mode, e.g.,π/2-Binary Phase-Shift Keying (BPSK), Quadrature Phase-Shift Keying(QPSK), 16-QAM, 64-QAM, or 256-QAM. In this way, modulation unit 412 maydetermine analog symbols from sequences of scrambled bits (i.e.,scrambled bit sequences). Resource mapper 416 may place analog symbolsin the frequency and time domain according to the allocated frequencybandwidth and time symbols for the transmission. The analog symbols mayinclude analog symbols determined by analog modulation unit 222 ofanalog compression unit 214 or analog symbols by modulation unit 412(e.g., analog symbols based on the scrambled bits, which may ultimatelybe based on the prediction data passing through quantization unit 206,entropy encoding unit 208, etc.). OFDM signal generation unit 418 mayapply an integer fast Fourier transform (iFFT) to the analog symbols,insert cyclic prefixes, and up-sample an analog signal to a radiofrequency (RF). When receiving data, the series of actions performed bythe units of modem 400 may be performed in reverse.

A digital path in modem 108 is a set of steps or units for transmittingdigital data. In the example of FIG. 4, the digital path includes TrBkCRC attachment unit 402, code block segmentation unit 404, channelcoding unit 406, rate matching unit 408, code block concatenation unit410, scrambler unit 412, modulation unit 414, resource mapper 416, andOFDM signal generation unit 418. In other examples, the digital path mayinclude more or fewer units or steps. An analog path in modem 108 mayinclude resource mapper 416 and OFDM signal generation unit 418, and notTrBk CRC attachment unit 402, code block segmentation unit 404, channelcoding unit 406, rate matching unit 408, code block concatenation unit410, scrambler unit 412, modulation unit 414.

FIG. 5 is an example constellation diagram 500 for analog modulation inan I-Q domain. Constellation diagram 500 is a representation of signalmodulation by quadrature amplitude modulation (QAM). Constellationdiagram 500 displays a signal as a 2-dimensional xy-plane scatterdiagram in a complex plane for a symbol sampling instant. In the contextof this disclosure, a symbol sampling instant corresponds to a moment intime during which an analog symbol is transmitted.

In the example of FIG. 5, the vertical axis of constellation diagram 500corresponds to a I-component, and therefore the real number component ofthe imaginary number. The horizontal axis of constellation diagram 500corresponds to a Q-component, and therefore the imaginary numbercomponent of the imaginary number.

The 2-dimensional plane of constellation diagram 500 is continuous(i.e., non-discrete). However, constellation diagram 500 contains a setof reference points 502A through 502P (collectively, “reference points502”). In the example of FIG. 5, the reference points are represented ascrosses. In the example of FIG. 6, the reference points are representedas circles. Reference points 502 may be shown as any arbitrary shapeused to represent points within the I-Q plane. In the example of FIG. 5,constellation diagram 500 includes a set of sixteen reference points502. For any point in constellation diagram 500 (including referencepoints 502 and non-reference points), the distance of the point from theorigin represents a measure of the amplitude or power of an analogsignal. The angle of a point as measured counterclockwise from thehorizontal axis (i.e., Q axis) represents a phase shift of a carrierwave from a reference phase.

Each of reference points 502 may correspond to a different bit sequencein an “alphabet” of bit sequences. Because there are sixteen referencepoints 502 in constellation diagram 500, the alphabet of bit sequencesmay be equal to 0000, 0001, 0010, 0011, 0100, 0101, 0110, 0111, 1000,1001, 1010, 1011, 1100, 1101, 1110, and 1111.

When modem 108 is transmitting digital data (e.g., entropy-encodedprediction data), modulation unit 412 (FIG. 4) may identify a referencepoint (e.g., one of reference points 502) that corresponds to a bitsequence (e.g., a scrambled bit sequence) based on the digital data. Forexample, if the bit sequence is equal to 0011 and reference point 502Dcorresponds to the bit sequence of 0011, modulation unit 412 maydetermine an analog symbol having the phase shift and powercorresponding to reference point 502K, e.g., as indicated by arrow 504.Resource mapper 414 and OFDM signal generation unit 416 of modem 108 mayuse the phase shift and amplitude during a symbol sampling instance whentransmitting the analog symbol in an analog signal, such as anelectrical signal or a radio signal.

When performing analog modulation on analog data (e.g., amplitude valuesgenerated by packing unit 220), analog modulation unit 222 of analogcompression unit 214 does not use reference points 502 of constellationdiagram 500. Rather, analog modulation unit 222 may determine a pair ofamplitude values generated by packing unit 220. Analog modulation unit222 may then use the amplitude value pair as the coordinates (e.g.,Cartesian coordinates) of a point in the I-Q plane. Analog modulationunit 222 may determine the analog symbol as the phase shift and power ofthe point indicated by the coordinates. Because analog modulation unit222 does not use reference points 502, the determined point may bebetween reference points 502, e.g., as shown by arrow 506.

Modem 122 of destination device 116 is configured to receive the analogsignal. When demodulating digital data (e.g., entropy-encoded predictiondata), modulation unit 414 may determine a phase shift and power of theanalog signal during a symbol sampling instant. Modulation unit 414 maythen determine a point in an I-Q plane of constellation diagram 500corresponding to the phase shift and power of the analog signal duringthe symbol sampling instant. Modulation unit 414 may then determine areference point (e.g., one of reference points 402) closest to thedetermined point. The determined point may not match the reference pointdue to noise during transmission. Modulation unit 414 may output (e.g.,to scrambler 412) the bit sequence corresponding to the determinedreference point. Remaining parts of modem 400 (e.g., scrambler 412, codeblock catenation unit 410, rate matching unit 412, channel coding unit414, code block segmentation 404, and TrBk CRC attachment unit 402) mayprocess the bit sequence to recover digital values.

Modem 122 (or, in the context of FIG. 4, resource mapper 416 of modem400) may determine an analog symbol corresponding to a phase shift andpower of the analog signal during a symbol sampling instant. Analogdemodulation unit 314 may then form a pair of amplitude values byassigning an I-coordinate of the determined point to a first amplitudevalue of the amplitude value pair and a Q-coordinate of the determinedpoint to a second amplitude value of the amplitude value pair. Thus,analog demodulation unit 314 may determine an amplitude value for thecoefficient vector as one of the coordinates of the analog symbol in anI-Q plane. Analog demodulation unit 314 may output the amplitude valuesof the amplitude value pair to unpacking unit 316.

FIG. 6 is a conceptual diagram illustrating received error during analogmodulation transmission. More specifically, FIG. 6 shows a constellationdiagram 600. Modem 400, analog modulation unit 222 and analogdemodulation unit 314 may use constellation diagram 600 in the samemanner as constellation diagram 500 of FIG. 5. In the example of FIG. 6,small circles are used in place of crosses to indicate reference points.Due to noise, the phase shifts and power, and hence analog symbols, maychange during transmission. However, small amounts of noise typically donot generate large displacements in terms of the amplitude valuescorresponding to the received analog symbol. In other words, thedifference between the original I-component and the I-componentcorresponding to the received analog symbol (i.e., ΔAmplitude₂) and thedifference between the original Q-component and the Q-componentcorresponding to the received analog symbol (i.e., ΔAmplitude₁) aretypically small during transmission of the analog symbol.

As discussed above, packing unit 220 may convert a coefficient vector toan amplitude value based on a mapping pattern. In some examples, theprocess for determining the amplitude value for a coefficient vector mayassume that each coefficient of the coefficient vector is an unsignedvalue. However, the coefficients in the coefficient vector may includepositive and negative values. Accordingly, packing unit 220 may performa process that converts the coefficients in the coefficient vector intounsigned values.

In some examples, packing unit 220 may use sign data coding to convertthe coefficients in the coefficient vector into unsigned values. Thatis, to convert the coefficients in the coefficient vector into unsignedvalues, packing unit 220 may determine sign values for each of thecoefficients in the coefficient vector. Additionally, packing unit 220may generate a modified coefficient vector containing the absolutevalues of the coefficients. In this example, packing unit 220 may thenuse the modified coefficient vector to determine the amplitude values.

Video encoder 200 may transmit the sign values via a digital path. Forinstance, video encoder 200 may transmit the sign values through thedigital path. Unpacking unit 316 of analog decompression unit 308 ofvideo decoder 300 may receive the sign values and may receive anamplitude value for the coefficient vector from analog demodulation unit314. Unpacking unit 316 may use the amplitude value for the coefficientvector to recover the modified coefficient vector. Unpacking unit 316may then reconstruct the original coefficient vector by setting thesigns of the coefficients in the modified coefficient vector to thecorresponding signs indicated in the sign data.

FIG. 7 is a conceptual diagram illustrating an example of data signcoding in accordance with one or more techniques of this disclosure. Inthe example of FIG. 7, a coefficient vector 700 includes positive andnegative coefficients. Packing unit 220 may generate sign data 702indicating the signs of coefficients in coefficient vector 700.Additionally, packing unit 220 may replace coefficient vector 700 with amodified coefficient vector 704 containing absolute values ofcoefficients in coefficient vector 700. Packing unit 220 may usemodified coefficient vector 704 to determine an amplitude value forcoefficient vector 700.

In some examples, packing unit 220 may use minimum-value coding toconvert the coefficients in a coefficient vector into unsigned values.For instance, to use minimum-value coding to convert the coefficients inthe coefficient vector into unsigned values, packing unit 220 maydetermine a shift value equal to a most-negative coefficient in thecoefficient vector. Packing unit 220 may then generate a modifiedcoefficient vector by adding an absolute value of the shift value toeach coefficient in the coefficient vector. Packing unit 220 may use themodified coefficient vector to determine an amplitude value for thecoefficient vector.

Packing unit 220 may transmit the shift value via the digital path.Unpacking unit 316 of analog decompression unit 308 of video decoder 300may receive the shift value and may receive an amplitude value for thecoefficient vector from analog demodulation unit 314. Unpacking unit 316may use the amplitude value for the coefficient vector to recover themodified coefficient vector. Unpacking unit 316 may then reconstruct theoriginal coefficient vector by adding the shift value to eachcoefficient in the modified coefficient vector.

FIG. 8 is a conceptual diagram illustrating an example of minimum-valuecoding in accordance with one or more techniques of this disclosure. Inthe example of FIG. 8, a coefficient vector 800 includes positive andnegative coefficients. Packing unit 220 determines a shift value 802.Shift value 802 may be a most-negative coefficient in coefficient vector800. Thus, in the example of FIG. 8, shift value 802 is equal to −13.Additionally, packing unit 220 may generate a modified coefficientvector 804 by adding the absolute value of the shift value to eachcoefficient in the coefficient vector. Video encoder 200 may transmitthe shift value, e.g., through the digital path.

FIG. 9 is a conceptual diagram illustrating an example mapping patternin accordance with one or more techniques of this disclosure. FIG. 10 isa conceptual diagram illustrating amplitude values corresponding to themapping pattern of FIG. 9, in accordance with one or more techniques ofthis disclosure. This disclosure may refer to the mapping pattern ofFIG. 9 and FIG. 10 as an S-Snake mapping pattern. Packing unit 220 andunpacking unit 316 may use the S-Snake mapping pattern to determineunsigned amplitude values for coefficient vectors of unsignedcoefficients that packing unit 220 converted from signed coefficients.Thus, the S-Snake mapping pattern is an example of a mapping patternthat maps unsigned coefficients to an unsigned amplitude value. Asmentioned above, packing unit 220 may determine an amplitude value for acoefficient vector based on a mapping pattern. The mapping pattern mapseach allowed coefficient vector to a unique amplitude value that isadjacent in an n-dimensional space to at least one other amplitude valuethat is adjacent to the unique amplitude value in a monotonic numberline of the amplitude values. In the example of FIG. 9 and FIG. 10, n isequal to 2.

In the example of FIG. 9, each of axes x and y correspond to differentcoefficients in a coefficient vector. Amplitude values increase by 1 foreach position along the chain of arrows starting from the positioncorresponding to a coefficient vector of (0, 0). For example, as shownin the example of FIG. 10, for a coefficient vector of (1, 10), packingunit 220 may determine that the corresponding amplitude value is 103.Similarly, unpacking unit 316 of may determine, based on an amplitudevalue of 103 that the corresponding coefficient vector is (1, 10). Asimilar type of mapping pattern may be extended into higher dimensions.

FIG. 11 is a conceptual diagram illustrating an example mapping patternin accordance with one or more techniques of this disclosure. FIG. 12 isa conceptual diagram illustrating amplitude values corresponding to themapping pattern of FIG. 11, in accordance with one or more techniques ofthis disclosure. This disclosure may refer to the mapping pattern ofFIG. 11 and FIG. 12 as an M-Snake mapping pattern. Packing unit 220 andunpacking unit 316 may use the M-Snake mapping pattern to determinesigned amplitude values for coefficient vectors of signed coefficients.Thus, the M-Snake mapping pattern is an example of a mapping patternthat maps signed coefficients to a signed amplitude value. Packing unit220 and unpacking unit 316 may use the mapping pattern of FIG. 11 andFIG. 12 in a similar manner as the mapping pattern of FIG. 9 and FIG.10. However, packing unit 220 and unpacking unit 316 may use the mappingpattern of FIG. 9 and FIG. 10 with coefficient vectors that includesigned values (i.e., positive and negative values). Because the mappingpattern of FIG. 9 and FIG. 10 can use coefficient vectors that includesigned values, video encoder 200 may not need to signal as much sideinformation (e.g., in the form of sign data or shift values). However,there may be some performance degradation associated with the use ofsigned values. For instance, signed coefficient may require anadditional bit relative to unsigned coefficients of the same resolution.This additional bit increases the signed signal amplitude dynamicrelative to unsigned coefficients (if unsigned coefficients were from 0,1, . . . , A, the signed coefficients with same resolution is −A, . . ., −1, 0, 1, . . . A)). As power is scaled to a nominal level, thescaling is more aggressive in respect to a signal with higher dynamicrange, thus performance may be lost.

A similar type of mapping pattern to that shown in FIG. 9 and FIG. 10may be extended into higher dimensions.

FIG. 13 is a conceptual diagram illustrating an example mapping patternin accordance with one or more techniques of this disclosure. FIG. 14 isa conceptual diagram illustrating amplitude values corresponding to themapping pattern of FIG. 13, in accordance with one or more techniques ofthis disclosure. This disclosure may refer to the mapping pattern ofFIG. 13 and FIG. 14 as an MS-Snake mapping pattern. Packing unit 220 andunpacking unit 316 may use the mapping pattern of FIG. 13 and FIG. 14 ina similar manner as the S-Snake mapping pattern of FIGS. 9 and 10. Likethe S-Snake mapping pattern, packing unit 220 may use the MS-Snakemapping pattern to convert coefficient vectors containing only unsignedvalue to signed amplitude values.

The MS-Snake mapping pattern may provide compression gain with smallvideo quality degradation. Moreover, the MS-Snake mapping pattern mayimprove noise resistance of the amplitude values. The MS-Snake mappingpattern maps unsigned numbers to signed amplitude values. Thus, theMS-Snake mapping pattern is an example of a mapping pattern that mapsunsigned coefficients to a signed amplitude value. When using theMS-Snake mapping pattern, the number of bits may remain the same, butthe dynamic power range may be reduced by 6 dB (as abs of max amplitudeis smaller by 1 bit). Power scaling may be less aggressive, which mayincrease the signal resiliency and may therefore improve noiseresistance. Additionally, the MS-Snake mapping pattern may introduce aunique noise suppression technique due to the use of multi-dimensionalshort arches. Using a 2D signed plane (of amplitude values) for mappingmay reduce the mapped amplitude by 1 bit in respect to signed mapping,resulting in a lower dynamic range, which an important property for ananalog modulated scheme for achieving a higher processing gain.

Although not illustrated in the figures of this disclosure, other typesof mapping patterns may map signed coefficients an to unsigned amplitudevalue.

FIG. 15 is a conceptual diagram illustrating an example 3-dimensionalmapping pattern 500 in accordance with one or more techniques of thisdisclosure. As mentioned above, packing unit 220 may determine anamplitude value for the coefficient vector based on a mapping pattern,where the mapping pattern maps each allowed coefficient vector to aunique amplitude value that is adjacent in an n-dimensional space to atleast one other amplitude value that is adjacent to the unique amplitudevalue in a monotonic number line of the amplitude values. In the exampleof FIG. 15, n is equal to 3. Packing unit 220 may use mapping pattern500 of FIG. 15 in a manner similar to the mapping patterns describedelsewhere in this disclosure. Mapping pattern 500 is an example of a3-dimensional S-Snake mapping pattern that maps vectors of unsignedcoefficients to unsigned amplitude values. For instance, where thecoefficient vector is equal to (0, 1, 2), packing unit 220 may determinean amplitude value of 62.

FIG. 16 is a flowchart illustrating an example method for encoding videodata in accordance with one or more techniques of this disclosure. Theflowcharts of this disclosure are presented as examples. Other examplesmay include more, fewer, or different actions, or actions may beperformed in different orders.

In the example of FIG. 16, video encoder 200 may generate coefficientsbased on video data (1600). For instance, in one example of generatingthe coefficient based on the video data, prediction unit 204 of videoencoder 200 may determine prediction data for the video data. In thisexample, residual generation unit 212 of video encoder 200 may generateresidual data indicating differences between sample values in theprediction block and corresponding sample values in the block of videodata. Furthermore, in this example, analog compression unit 214 maygenerate coefficients based on the residual data. For instance,binarization unit 216 of video encoder 200 may binarize the residualdata to generate coefficients and quantization unit 218 may quantize thecoefficients. In other examples of generating coefficients based onvideo data, video encoder 200 may perform more, fewer, or differentsteps. For instance, in some examples, video encoder 200 does notperform a quantization step. In still other examples, video encoder 200does not perform a step of binarizing the residual data.

In some examples, video encoder 200 may generate digital values (e.g.,bit sequences) based on the prediction data and modem 108 (e.g.,modulation unit 414 of modem 108) may be configured to transmit thedigital values. For instance, quantization unit 206 may generatequantized digital sample values based on digital sample values in theprediction data. Entropy encoding unit 208 may perform anentropy-encoding process that generates the digital values based on thequantized digital sample values. To transmit the digital values, modem108 may generate bit sequences based on the entropy-encoded data, e.g.,as described with respect to FIG. 4. Modulation unit 414 may determineanalog symbols based on the bit sequences.

In some examples, analog compression unit 214 may modify initialcoefficients to generate the coefficients. In one example consistentwith FIG. 7, analog compression unit 214 (e.g., binarization unit 216and/or quantization unit 218) may generate initial coefficients based onthe video data. In this example, analog compression unit 214 maygenerate sign values indicating positive/negative signs of the initialcoefficients. Furthermore, analog compression unit 214 may generate thecoefficients as absolute values of the initial coefficients. In thisexample, modem 108 may be configured to signal data representing thesign values.

In another example of modifying the initial coefficients that isconsistent with FIG. 8, the coefficients in the coefficient vector arenon-negative versions of initial coefficients. In this example, as partof generating the coefficients based on the video data (e.g., based onresidual data), analog compression unit 214 (e.g., binarization unit 216and/or quantization unit 218) may generate the initial coefficientsbased on the residual data. In this example, analog compression unit 214may determine a shift value (e.g., shift value 802 of FIG. 8) based on amost-negative initial coefficient of the initial coefficients. Analogcompression unit 214 may perform a process that transforms the initialcoefficients based on the shift value to the non-negative versions ofthe initial coefficients. In this example, modem 108 may be configuredto signal data representing the shift value.

Furthermore, in the example of FIG. 16, packing unit 220 of videoencoder 200 may generate coefficient vectors (1602). Each of thecoefficient vectors includes n of the coefficients. Packing unit 220 maygenerate the coefficient vectors in one of a variety of ways. Forinstance, in one example, packing unit 220 may generate a coefficientvector as a group of n consecutive coefficients according to acoefficient coding order. Various coefficient coding orders may be used,such as raster scan order, zigzag scan order, reverse raster scan order,vertical scan order, and so on. In some examples, a coefficient vectormay include one or more negative coefficients and one or more positivecoefficients (i.e., signed coefficients). In some examples, acoefficient vector only includes non-negative coefficients (i.e.,unsigned coefficients).

For each of the coefficient vectors, packing unit 220 may determine anamplitude value for the coefficient vector based on a mapping pattern(1604). For each respective allowed coefficient vector in a plurality ofallowed coefficient vectors, the mapping pattern maps the respectiveallowed coefficient vector to a respective amplitude value in aplurality of amplitude values. The respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values.FIGS. 9-15, which are discussed above, show example mapping patternsthat packing unit 220 may use to determine amplitude values forcoefficient vectors. Thus, in some examples, the mapping pattern may beone of an S-Snake pattern, an M-Snake pattern, an MS-Snake pattern, oranother type of mapping pattern. The value n may be greater than orequal to 2.

In some examples, to determine the amplitude value for the coefficientvector, packing unit 220 may determine a position in the n-dimensionalspace. Coordinates of the position in the n-dimensional space are basedon the coefficients of the coefficient vector, and the mapping patternmaps different positions in the n-dimensional space to differentamplitude values in the plurality of amplitude values. Packing unit 220may determine the amplitude value for the coefficient vector as theamplitude value corresponding to the determined position in then-dimensional space.

In some examples, video encoder 200 may dynamically switch betweenmapping patterns according to one or more optimization criteria. Forexample, video encoder 200 may use the mapping pattern of FIGS. 9 and 10when greater performance is required and may use the mapping pattern ofFIGS. 11 and 12 when it is more desirable to send less side information.In this example, the performance may be measured in terms of noiseresiliency, numbers of bits per analog symbol, or according to someother metric. In this example, video encoder 200 may switch betweenmapping patterns on a block-by-block basis, on a picture-by-picturebasis, a sequence-by-sequence basis, or on another basis. In anotherexample, video encoder 200 may dynamically switch between mappingpatterns, e.g., in the manner described with respect to FIGS. 24-26.

Analog modulation unit 222 may then modulate an analog signal based onthe amplitude values for the coefficient vectors (1606). Analogmodulation unit 222 may perform analog amplitude modulation inaccordance with any of the examples provided elsewhere in thisdisclosure, e.g., the examples described with respect to FIG. 5 and FIG.6. For instance, analog modulation unit 222 may determine an analogsymbol based on a pair of the amplitude values. The analog symbol maycorrespond to a phase shift and a power of a point in an I-Q plane thathaving coordinates indicated by the amplitude value pair. Analogmodulation unit 222 may modulate the analog signal during a symbolsampling instant based on the determined phase shift and power. Modem108 may be configured to output the analog signal (1608).

FIG. 17 is a flowchart illustrating an example method for decoding videodata in accordance with one or more techniques of this disclosure. Inthe example of FIG. 17, analog demodulation unit 314 of video decoder300 may determine, based on an analog signal, amplitude values for aplurality of coefficient vectors (1700). Analog demodulation unit 314may perform the analog amplitude demodulation in accordance with any ofthe examples provided elsewhere in this disclosure, e.g., the examplesdescribed with respect to FIG. 5 and FIG. 6. For instance, analogdemodulation unit 314 may determine a phase shift and a power for asymbol sampling instant of the analog signal. Analog demodulation unit315 may determine a point in an I-Q plane indicated by the determinedphase shift and power. Analog demodulation unit 314 may then determinean amplitude value pair as the coordinates in the point in the I-Qplane.

For each of the coefficient vectors, unpacking unit 316 may determinecoefficients in the coefficient vector based on the amplitude value forthe coefficient vector and a mapping pattern (1702). For each respectiveallowed coefficient vector in a plurality of allowed coefficientvectors, the mapping pattern may map the respective allowed coefficientvector to a respective amplitude value in a plurality of amplitudevalues. The respective amplitude value is adjacent in an n-dimensionalspace to at least one other amplitude value in the plurality ofamplitude values that is adjacent to the respective amplitude value in amonotonic number line of the amplitude values. Each of the coefficientvectors may include n of the coefficients. FIGS. 9-15, which arediscussed above, show example mapping patterns that unpacking unit 316may use to determine amplitude values for coefficient vectors. Thus, insome examples, the mapping pattern may be one of an S-Snake pattern, anM-Snake pattern, an MS-Snake pattern, or another type of mappingpattern. The value n may be greater than or equal to 2. In someexamples, unpacking unit 316 may determine the coefficients in thecoefficient vector as coordinates of a position in the n-dimensionalspace that corresponds to the amplitude value, wherein the mappingpattern maps different positions in the n-dimensional space to differentamplitude values in the plurality of amplitude values. In some examples,the coefficient vector includes one or more negative coefficients andone or more positive coefficients. In other examples, the coefficientvector may include only non-negative coefficients.

In some examples, such as the example of FIG. 7, as part of determiningthe coefficients, video decoder 300 may obtain sign values (e.g., via adigital path of modem 122), where the sign values indicatepositive/negative signs of the coefficients in the coefficient vector.In such examples, video decoder 300 may determine, based on theamplitude value for the coefficient vector and the mapping pattern,absolute values of the coefficients in the coefficient vector. Videodecoder 300 may reconstruct the coefficients in the coefficient vectorat least in part by applying the sign values to the absolute values ofthe coefficients in the coefficient vector. In some example, such as theexample of FIG. 8, as part of determining the coefficients, videodecoder 300 may obtain (e.g., via a digital path of modem 122), datarepresenting a shift value. In such examples, the shift value indicatesa most-negative coefficient of the coefficients in the coefficientvector. Additionally, in such examples, video decoder 300 may determine,based on the amplitude value for the coefficient vector and the mappingpattern, intermediate values of the coefficients in the coefficientvector. Video decoder 300 may reconstruct the coefficients in thecoefficient vector at least in part by adding the shift value to each ofthe intermediate values of the coefficients in the coefficient vector.

Furthermore, in the example of FIG. 17, video decoder 300 may generatevideo data based on the coefficients in the coefficient vectors (1704).For instance, in one example, dequantization unit 318 of video decoder300 may dequantize the coefficients of the coefficient vectors. In thisexample, de-binarization unit 320 of video decoder 300 may perform ade-binarization process to convert the coefficients into digital samplevalues. For instance, de-binarization unit 320 may apply an inverse DCTto the coefficients to convert the coefficients into digital samplevalues. In this way, analog decompression unit 308 may generate digitalsample values. Furthermore, in this example, entropy decoding unit 304of video decoder 300 may obtain digital values (e.g., via digital pathof modem 122). Video decoder 300 may generate prediction data based onthe digital values. For instance, entropy decoding unit 304 may performan entropy decoding process on the digital values to generate quantizeddigital sample values. Dequantization unit 306 of video decoder 300 maygenerate the prediction data by dequantizing the quantized digitalsample values. Reconstruction unit 310 of video decoder 300 may generatevideo data based on the prediction data and the residual data, e.g., byadding corresponding digital sample values of the prediction block andthe digital sample values generated by analog decompression unit 308. Inthis way, video decoder 300 is able to generate video data based on thecoefficients in the coefficient vectors. In other examples, videodecoder 300 may perform more, fewer, or different actions. For instance,in some examples, the dequantization steps performed by dequantizationunit 306 and/or dequantization unit 318 are omitted. In some examples,video decoder 300 may omit the entropy decoding process performed byentropy decoding unit 304.

In accordance with one or more techniques of this disclosure, packingunit 220 may perform an interlacing process that unifies multiplecoefficients into a single amplitude value. Performing the interlacingprocess may improve noise resistance and may provide compression gainrelative to using two or more different symbol sampling instants to sendtwo or more non-interlaced analog symbols. Packing unit 220 may performthe interlacing process to generate amplitude values instead of theprocess described elsewhere in this disclosure that uses a mappingpattern to generate amplitude values for coefficient vectors.

FIG. 18 is a conceptual diagram illustrating a first example ofinterlacing, in accordance with one or more techniques of thisdisclosure. In the example of FIG. 18, a first coefficient 1800 consistsof four bits (i.e., bits a₀ through a₃) and a second coefficient 1802consists of four bits (i.e., b₀ through b₃). In general, interlacingrefers to inserting bits of one or more coefficients (e.g., in analternating pattern, a round robin pattern, or other type of pattern)between bits of another coefficient. Packing unit 220 of video encoder200 may perform an interlacing process that generates an amplitude value1804 by interlacing the bits of coefficient 1800 with the bits ofcoefficient 1802. This disclosure may refer to amplitude valuesgenerated by performing the interlacing process as “interlaced amplitudevalues.”

Analog modulation unit 222 may use pairs of interlaced amplitude valuesin the same manner as amplitude values described elsewhere in thisdisclosure. Unpacking unit 316 of video decoder 300 may receiveinterlaced amplitude values from analog demodulation unit 314 and mayperform a deinterlacing process that reconstructs coefficients from theinterlaced amplitude values. For instance, in the context of FIG. 18,unpacking unit 316 may perform a deinterlacing process that reconstructscoefficients 1800 and coefficient 1802 from interlaced amplitude value1804.

FIG. 19 is a conceptual diagram illustrating a second example ofinterlacing, in accordance with one or more techniques of thisdisclosure. In the example of FIG. 19, packing unit 220 of video encoder200 performs an interlacing process that interlaces the bits ofcoefficients 1900, 1902, 1904, and 1906 to generate an interlacedamplitude value 1908. Unpacking unit 316 of video decoder 300 performs adeinterlacing process that deinterlaces the bits of interlaced amplitudevalue 1908 to form coefficients 1900, 1902, 1904, and 1906.

In some examples, packing unit 220 may dynamically select amongdifferent interlacing processes. As one can see from FIG. 18 and FIG.19, interlaced amplitude values can include different numbers of bitsdepending on the interlacing process used to generate amplitude valuesfrom coefficients. Various characteristics of a channel through whichsource device 102 is transmitting the analog signal may dictate thespectral efficiency of the channel. The spectral efficiency of thechannel indicates how many bits can be used in an amplitude value. Forinstance, if there is greater noise in the channel, the spectralefficiency may be lower and hence amplitude values may have fewer bits.Therefore, packing unit 220 may determine a value x based on thespectral efficiency of the channel and the number of bits percoefficient. For instance, packing unit 220 may determine the value x asthe spectral efficiency divided by the number of bits per coefficient.Packing unit 220 may then use an interlacing process that interlaces thebits of x coefficients to form an interlaced amplitude value. In thisway, packing unit 220 may select, based on a spectral efficiency of achannel through which the analog signal is transmitted, the interlacingprocess from a plurality of interlacing processes. Unpacking unit 316 ofvideo decoder 300 may select the deinterlacing process from a pluralityof deinterlacing processes. For instance, video encoder 200 may signal(e.g., via the digital path) data indicating the interlacing process. Insome examples, each of the deinterlacing processes deinterlaces adifferent number of coefficients from the interlaced amplitude value.

Interlaced amplitude values can be noise sensitive at specific values.For instance, changes in power or phase of an analog signal during asymbol sampling instant may result in the addition of 1 to an interlacedamplitude value that analog demodulation unit 314 determines for thesymbol sampling instant. The change in the packed amplitude value canresult in significant differences between the original digital samplevalues and the digital sample values derived from the interlacedamplitude value.

FIG. 20 is a block diagram illustrating example effects of noise on acoding process. In the example of FIG. 20, binarization unit 216 ofvideo encoder 200 may receive two digital sample values, each equal to7. Binarization unit 216 may convert the digital sample values tocoefficients, both equal to 0111. Packing unit 220 may perform aninterlacing process that interlaces bits of the coefficients to generatean interlaced amplitude value of 0011_1111 (which is equal 63 indecimal). Analog modulation unit 222 (labeled D2A, for digital toanalog, in FIG. 20) may then perform analog modulation to modulate ananalog signal based on the interlaced amplitude value. The analog signalmay be transmitted via a channel 2000.

During transmission of the analog signal through channel 2000, noise maycause a 1-bit change to the interlaced amplitude value demodulated fromthe analog signal by analog demodulation unit 314 (labeled A2D, foranalog to digital, in FIG. 20). For instance, changes in power or phaseshift of the analog signal during a symbol sampling instant may causeanalog demodulation unit 314 to determine a point in an I-Q plane thatis different from the point in the I-Q plane corresponding to anoriginal amplitude value pair. Thus, an interlaced amplitude valuedetermined by analog demodulation unit 314 may be equal to 64 instead of63. As shown in the example of FIG. 20, the interlaced amplitude valuemay be represented in binary as 0100_0000. Unpacking unit 316 mayperform a deinterlacing process that converts the interlaced amplitudevalue of 0100_0000 into coefficients 0000 and 1000. De-binarization unit320 may convert these coefficients into digital sample values, which inthe example of FIG. 20 are equal to 0 and 8. Note that the digitalsample values of 0 and 8 differ significantly from the original digitalsample values of 7 and 7. This difference may have serious adverseeffects on the quality of a decoded picture based on these digitalsample values. It is noted that this noise vulnerability occursprimarily with respect to specific interlaced amplitude values. However,this noise vulnerability is not so serious at other interlaced amplitudevalues.

In accordance with one or more techniques of this disclosure that mayaddress this issue, packing unit 220 may remap interlaced amplitudevalues to alternate interlaced amplitude values such that there are gapvalues in a number line of the interlaced amplitude values at positionsbetween noise-vulnerable interlaced amplitude values in a number line ofthe interlaced amplitude values. The noise-vulnerable interlacedamplitude values in the number line of the interlaced amplitude valuesare interlaced amplitude values in which adding minimal noise (e.g., a1-bit flip) may cause significant changes to the digital sample valuesdetermined based on the interlaced amplitude values. When analogdemodulation unit 314 determines that an interlaced amplitude valuedemodulated from the analog signal is one of the gap values, analogdemodulation unit 314 may round the interlaced amplitude value to anearest one of the non-gap interlaced amplitude values.

FIG. 21 is a conceptual diagram illustrating gap ranges in accordancewith one or more techniques of this disclosure. In the example of FIG.21, number line 2100 corresponds to a range of interlaced amplitudevalues. Each block in number line 2100 may correspond to series ofinterlaced amplitude values between noise-vulnerable interlacedamplitude values. Number line 2100 conceptually illustrates theinsertion of gap values between noise-vulnerable interlaced amplitudevalues. Specifically, in the example of FIG. 21, dark bars correspond toranges of gap values (i.e., gap ranges). The widths of the ranges of gapvalues may be correlated with (e.g., proportional to or having someother relationship with) the number of changed bits in a binaryrepresentation of an interlaced amplitude value from noise that changesa decimal value of the interlaced amplitude value by one value. Forinstance, as shown in number line 2104 of FIG. 21, 2 gap values may beinserted between 15 and 16, 4 gap values may be inserted between 31 and32, 2 gap values may be inserted between 47 and 48, and so on.

Thus, as shown in number line 2106 of FIG. 21, analog modulation unit222 may map interlaced amplitude values 0-15 to alternate interlacedamplitude values 0-15, interlaced amplitude values 16-31 to alternateinterlaced amplitude values 18-33, interlaced amplitude values 32-47 toalternate interlaced amplitude values 38-53, interlaced amplitude values48-63 to alternate interlaced amplitude values 56-71, and so on.Accordingly, analog demodulation unit 314 may convert alternateinterlaced amplitude values 0-15 back to corresponding interlacedamplitude values 0-15; convert alternate interlaced amplitude values16-17 (i.e., gap values) to interlaced amplitude values 15 and 16,respectively, convert alternate interlaced amplitude values 18-33 backto corresponding interlaced amplitude values 16-31; convert alternateinterlaced amplitude values 34-35 (i.e., gap values) to interlacedamplitude value 31; convert alternate interlaced amplitude values 36-37(i.e., gap values) to interlaced amplitude value 32; convert alternateinterlaced amplitude values 38-53 to corresponding interlaced amplitudevalues 32-37; and so on.

FIG. 22 is a flowchart illustrating an example method for encoding videodata in accordance with one or more techniques of this disclosure. Inthe example of FIG. 22, prediction unit 204 may generate prediction datafor the video data (2200). Additionally, residual generation unit 212may generate residual data based on the prediction data and digitalsample values of the video data (2202). For example, residual generationunit 212 may subtract digital sample values of the prediction data fromcorresponding digital sample values of the video data to generatedigital sample values of the residual data.

Analog compression unit 214 may generate coefficients based on theresidual data (2204). For example, binarization unit 216 may perform abinarization process that generates the coefficients based on theresidual data. In this example, quantization unit 218 may perform aquantization process that quantizes the coefficients.

In accordance with a technique of this disclosure, packing unit 220 mayperform an interlacing process to generate an interlaced amplitude value(2206). The interlacing process interlaces bits of two or more of thecoefficients to generate the interlaced amplitude value. For instance,in the example of FIG. 19, the interlacing process interlaces the bitsof two of the coefficients to generate the interlaced amplitude value.In the example of FIG. 20, the interlacing process interlaces the bitsof four of the coefficients to generate the interlaced amplitude value.In some examples, packing unit 220 selects, based on a spectralefficiency of a channel through which the analog signal is transmitted,the interlacing process from a plurality of interlacing processes. Insome such examples, each of the interlacing processes interlaces adifferent number of the coefficients to generate the interlacedamplitude value.

Furthermore, video encoder 200 may be configured to generate digitalvalues based on the prediction data (2208). For instance, quantizationunit 206 may generate quantized digital sample values based on digitalsample values in the prediction data. In this example, entropy encodingunit 208 may perform an entropy-encoding process that generates thedigital values based on the quantized digital sample values.

Modem 108 may be configured to output one or more analog signals thatare modulated based on the interlaced amplitude values and the digitalvalues (2210). For instance, analog modulation unit 222 may determine ananalog symbol corresponding to an amplitude value pair that includes theinterlaced amplitude value. Modem 108 may transmit an analog signalduring a symbol sampling instant based on a phase shift and powercorresponding to the analog symbol. Modem 108 may also transmit ananalog signal based on the digital values, e.g., in the manner describedwith respect to FIG. 4.

In some examples, analog modulation unit 222 performs a mapping processthat maps the interlaced amplitude value from an original number line(e.g., number line 2100 of FIG. 21) to a mapped value in an alternatenumber line (e.g., alternate number line 2106 of FIG. 21) that includesone or more gap ranges. The gap ranges may be located at positions inthe original number line correlated with impacts of noise in terms ofbit flips in interlaced amplitude values demodulated from analogsignals. The mapping process does not map any interlaced amplitude valueto any value in any of the one or more gap ranges. Analog modulationunit 222 may generate an amplitude value pair that includes the mappedvalue. Analog modulation unit 222 may then determine an analog symbolbased on the mapped value. Modem 108 may modulate an analog signal basedon the analog symbol. Thus, modem 108 may modulate an analog signalbased on the mapped value.

FIG. 23 is a flowchart illustrating an example method for decoding videodata in accordance with one or more techniques of this disclosure. Inthe example of FIG. 23, analog demodulation unit 314 may determine aninterlaced amplitude value based on an analog signal (2300). In someexamples, as part of determining the interlaced amplitude value based onthe analog signal, modem 112 may determine an analog symbolcorresponding to a phase shift and power for a symbol sampling instantof the analog signal. The interlaced amplitude value may be anI-component or a Q-component of the coordinates of the analog symbol inan I-Q plane.

In some examples, a mapped value may be the I-component or Q-componentof the coordinates of the analog symbol in the I-Q plane. The mappedvalue may have been generated using a mapping process that mapsinterlaced amplitude values in an original number line (e.g., numberline 2100 of FIG. 21) to mapped values in an alternate number line(e.g., alternate number line 2106 of FIG. 21) that includes one or moregap ranges. The gap ranges may be located at positions in the originalnumber line correlated with impacts of noise in terms of bit flips ininterlaced amplitude values demodulated from analog signals and themapping process does not map any of the interlaced amplitude values toany value in any of the one or more gap ranges. In this example, analogdemodulation unit 314 may use an inverse of the mapping process to mapthe mapped value to the interlaced amplitude value. In some instances,the mapped value determined by demodulating the analog signal is in oneof the gap ranges. In such instances, the inverse of the mapping processmaps mapped values in the gap ranges to interlaced amplitude values inthe original number line. In this way, analog demodulation unit 314 maybe able to reduce the impact of noise on the analog signal.

Thus, in such examples, analog demodulation unit 314 may demodulate theanalog signal to determine a mapped value generated using a mappingprocess that maps interlaced amplitude values in an original number lineto mapped values in an alternate number line that includes one or moregap ranges, wherein the gap ranges are located at positions in theoriginal number line correlated with impacts of noise in terms of bitflips in interlaced amplitude values demodulated from analog signals andthe mapping process does not map any of the interlaced amplitude valuesto any value in any of the one or more gap ranges. Analog demodulationunit 314 may use an inverse of the mapping process to map the mappedvalue to the interlaced amplitude value.

Furthermore, in the example of FIG. 23, unpacking unit 316 may perform adeinterlacing process to generate two or more coefficients (2302). Bitsof the two or more coefficients are interlaced in the interlacedamplitude value. In some examples, the deinterlacing processdeinterlaces the bits of two of the coefficients (e.g., the reverse ofthe interlacing process shown in the example of FIG. 18). In someexamples, the deinterlacing process deinterlaces the bits of four of thecoefficients (e.g., the reverse of the interlacing process shown in theexample of FIG. 19) from the interlaced amplitude value. In someexamples, unpacking unit 316 may select, based on data transmitted inone or more analog signal, the deinterlacing process from a plurality ofdeinterlacing processes. In some such examples, each of thedeinterlacing processes deinterlaces a different number of thecoefficients.

Analog decompression unit 308 may generate residual data based on thetwo or more coefficients (2304). For instance, dequantization unit 318may perform an inverse quantization process that inverse quantizes thecoefficients. De-binarization unit 320 may perform a de-binarizationprocess that generates the residual data based on the coefficients.

Additionally, video decoder 300 may obtain digital values (2306). Forinstance, modem 122 may be configured to obtain the digital values andprovide the digital values to video decoder 300. Video decoder 300 maygenerate prediction data based on the digital values (2308). Forinstance, entropy decoding unit 304 may perform an entropy-decodingprocess that generates quantized digital sample values based on thedigital values. Dequantization unit 306 may perform an inversequantization process that generates digital sample values in theprediction data based on the inverse quantized digital sample values.Reconstruction unit 310 of video decoder 300 may reconstruct the videodata based on the prediction data and the residual data (2310). Forinstance, reconstruction unit 310 may add digital sample values of theprediction data to corresponding digital sample values of the residualdata to reconstruct digital sample values of the video data.

FIG. 24 is a block diagram illustrating an example analog compressionunit 2400 that uses a variable symbol rate, in accordance with one ormore techniques of this disclosure. Analog compression unit 2400 may beused in place of analog compression unit 214 of FIG. 2. In the exampleof FIG. 24, analog compression unit 2400 may include a blocksegmentation unit 2402, a block dynamic quantization unit 2404, aspectral efficiency unit 2406, a packing unit 2408, a scaling unit 2410,and an analog modulation unit 2412.

Block segmentation unit 2402 may receive residual data and segment theresidual data into 2-dimensional blocks. In other words, blocksegmentation unit 2402 may divide a residual image of size N into N/Kblocks, where K indicates the number of coefficients per block. The Kcoefficients per block i may be denoted as b_(0,i), b_(1,i) . . .b_(k,i), where i=0, 1, . . . , N/K−1. In some examples, blocksegmentation unit 2404 may adaptively select the sizes of blocks basedon one or more characteristics of the content of the blocks. Forinstance, block segmentation unit 2404 may select a larger block sizefor blocks in a region of a picture that contains relatively uniformdigital sample values and may select smaller block sizes for regions ofthe picture that contain less uniform digital sample values. In someexamples, block segmentation unit 2402 may apply a transform to theresidual data of a block to generate coefficients of the block. Forinstance, block segmentation unit 2402 may apply a DCT (e.g., an integerDCT) or other transform to the residual data of a block to generatecoefficients of the block. In some examples, the coefficients of theblock may be residual digital sample values.

For each block i, block dynamic quantization unit 2404 may quantizeblock i to generate quantized coefficients, each of which consists of Qbits. The value of Q may be different for different blocks. Thus, thisdisclosure may denote the number of bits used to quantize coefficientsof block i as Q_(i). The quantized coefficients c of block i (whereblock i has size k) are denoted as c_(0,i), c_(1,i), . . . , c_(k,i).

In some examples, block dynamic quantization unit 2404 may quantizecoefficients of a block based on a total entropy of the picture. Forexample, if the picture includes large areas of homogenous color (e.g.,a large area of blue sky), the total entropy of the picture may berelatively low. Hence, when the total entropy of the picture isrelatively low, higher levels of quantization may be used withoutsignificantly reducing the quality of the picture when decoded. Usinghigher levels of quantization may reduce the amount of informationneeded to represent the encoded version of the picture. However, if thepicture includes large areas of complex and sharply varying colors, thetotal entropy of the picture may be relatively high. Hence, when thetotal entropy of the picture is relatively high, higher levels ofquantization may significantly reduce the quality of the picture whendecoded. In some examples, block dynamic quantization unit 2404 may usea predefined mapping or formula to translate entropy to a quantizationparameter that block dynamic quantization unit 2404 uses to quantize thecoefficients of the block. In some examples, block dynamic quantizationunit 2404 may quantize the block based on the total entropy of the blockitself instead of the total entropy of the picture.

At least partially because block dynamic quantization unit 2404 appliesdynamic quantization to the blocks, the number of bits per block (i.e.,the number of bits representing each of the quantized coefficients in ablock) may vary from block to block. In the example of FIG. 22, block2414 represents the number of bits.

Spectral efficiency unit 2406 may determine the spectral efficiency of achannel through which source device 102 will send the analog symbols.Methods for determining spectral efficiency may be defined in certaintransmission standards, such as the 5G standard. Spectral efficiency mayindicate how many bits source device 102 can convey through the channelto destination device 116 in an amplitude value during a symbol samplinginstant. In other words, the spectral efficiency may correspond to thenumber of bits that may be used in an amplitude value.

The spectral efficiency of the channel may change over time. Forinstance, the spectral efficiency of the channel may change due toenvironmental conditions (e.g., rain, mist, snow, etc.). In someinstances, the spectral efficiency of the channel may change when sourcedevice 102 and/or destination device 116 moves into or out of abuilding. In some instances, the spectral efficiency of the channel maychange when source device 102 and/or destination device 116 moves closeror further from a wireless base station. In some instances, the spectralefficiency of the channel may change due to reflections off buildings ornatural features.

In some examples, modem 108 may send and receive data using a MultipleInput-Multiple Output (MIMO) method. When transmitting data using a MIMOmethod, modem 108 may use multiple antennas to send and receive data.Sending data via different antennas may be analogous to sending the datavia different channels. There may be different spectral efficiencies forthese different channels. In this context, the different channels usedin MIMO may be referred to as layers. Hence, spectral efficiency unit2406 may determine different spectral efficiencies for each layer.

Similar to the discussion above regarding packing unit 220, packing unit2408 may generate coefficient vectors and determine amplitude values forthe coefficient vectors based on a mapping pattern. In the context ofFIG. 24, each coefficient in a coefficient vector belongs to the sameblock. In some instances, there may be a single coefficient vector for ablock. In other examples, there may be multiple coefficient vectors fora block. Moreover, similar to the discussion above regarding analogmodulation unit 222, analog modulation unit 2412 may determine an analogsymbol based on pairs of amplitude values. Analog modulation unit 2412may modulate an analog signal based on the analog symbol.

In examples where modem 108 uses a MIMO method, the analog symbolsdetermined by analog modulation unit 2412 based on amplitude values maybe distributed among the different layers. In examples where modem 108does not use MIMO (e.g., when only a single antenna is used), there mayonly be a single layer and spectral efficiency unit 2406 may determine aspectral efficiency of this single layer. In either case, modem 108 mayuse the same layer to transmit an analog signal representing the analogsymbols based on amplitude values for coefficient vectors containingcoefficients of the same block (i.e., block i). Hence, the spectralefficiency of the layer through which the analog symbols determinedbased on the amplitude values for coefficient vectors containingquantized coefficients of block i are sent may be denoted as SE_(i).Similarly, the bits per block for block i may be denoted as Q_(i).

Packing unit 2408 may use the spectral efficiency per layer 2416(SE_(i)) and bits per block 2414 (Q_(i)) for block i when packing unit2408 is performing a packing operation to convert a coefficient vectorcontaining quantized coefficients of the block into an amplitude value.More specifically, packing unit 2408 may dynamically select, e.g., on ablock-by-block basis, the dimensionality of the mapping pattern thatpacking unit 2408 uses to determine an amplitude value for a coefficientgroup. Stated another way, packing unit 2408 may dynamically select,e.g., on a block-by-block basis, the number of coefficients n in eachcoefficient vector. Because a higher value of n may lead to greatercompression in terms of number of bits used to represent the amplitudevalue for a coefficient vector relative to the number of bits used torepresent the coefficients in the coefficient vector, and because lowervalues of n may lead to less compression, the amplitude valuesdetermined by packing unit 2408 may have a variable bit rate. The valuen for a block i may be denoted as n_(i).

As mentioned above, packing unit 2408 may determine the mapping patternbased on the bits per block 2414 (i.e., Q_(i)) and the spectralefficiency per layer 2416 (i.e., SE_(i)). For example, packing unit 2408may use a predefined 2-dimensional table having one dimension for SE_(i)and one dimension for Q_(i). Values in cells of the table indicate thevalue of n_(i) (i.e., the number of coefficients in a coefficient vectorcontaining coefficients of block i). In some examples, packing unit 2408may determine the value of n_(i) by dividing SE_(i) by Q_(i). In otherwords, SE_(i) may be approximately equal to n_(i) multiplied by Q_(i).

In some examples, packing unit 2408 may determine the value n_(i) basedon SE_(i) and Q_(i). Packing unit 2408 may determine a mapping patternthat uses a n_(i)-dimensional space. In some examples, packing unit 2408may select from among multiple mapping patterns that use the samen_(i)-dimensional space. In some examples, the mapping pattern may beasymmetric in the sense that there may be more allowed values (e.g.,allowed values of quantized coefficients) in some dimensions than otherdimensions. For instance, with reference to the example of FIG. 9, theremay be more available numbers in the x axis than in the y axis. The useof such asymmetric mapping patterns may be useful in examples whereQ_(i) for block i is different from Q_(i) for a block j. In an examplewhere Q_(i) is equal to 2 and SE_(i) is equal to 8 bits, four quantizedcoefficients (i.e., n_(i)=4) that each contain 2 bits (i.e., Q_(i)=2)can be packed into a single 8-bit amplitude value. In another example,if SE_(i) is equal to 8 bits, Q_(i) is equal to 4, and Q₁ is equal to 2,packing unit 2408 may pack one quantized coefficient of block i and 2quantized coefficients of block j to generate a single amplitude value.

Because the value of n may change from block to block, video encoder 200may transmit the value of n to video decoder 300. In some examples,video encoder 200 may transmit the value of n through the digital path.In some examples, video encoder 200 may transmit the value of n when thevalue of n changes but does not necessarily transmit the value of nseparately for each block.

Power scaling unit 2410 multiplies the amplitude values by dynamicallyselected scaling values. In this way, power scaling unit 2410 maygenerate scaled amplitude values. Power scaling unit 2410 may select thescaling values to ensure consistent power output of the amplitudevalues. Furthermore, in the example of FIG. 24, analog modulation unit2412 may modulate an analog signal based on the scaled amplitude values.For instance, in some examples, analog modulation unit 2412 maydetermine an analog symbol based on a pair of the scaled amplitudevalues. Modem 108 may transmit the analog signal such that during asymbol sampling instant corresponding to the analog symbol, the analogsignal has the phase shift and power corresponding to the analog symbol.

An analog decompression unit configured to work with respect to theanalog compression unit 2400 of FIG. 24 may generally operate in amanner similar to analog decompression unit 308 (and components thereof)as discussed elsewhere in this disclosure. However, in some examples,unpacking unit 316 may obtain an indication of the value of n (whichvideo encoder 200 may signal via the digital path) and may use anappropriate mapping pattern for the received value of n to unpackcoefficients from amplitude values.

FIG. 25 is a flowchart illustrating an example method for encoding videodata in accordance with one or more techniques of this disclosure. Inthe example of FIG. 25, video encoder 200 may generate coefficientsbased on digital sample values of the video data (2500). In someexamples, as part of generating the coefficients based on the videodata, prediction unit 204 (FIG. 2) may generate prediction data for thevideo data. Residual generation unit 212 may generate residual databased on the prediction data and digital sample values of the videodata. Analog compression unit 214 may generate the coefficients based ona block of digital sample values in the residual data. For instance,binarization unit 216 may perform a binarization process that generatesthe coefficients based on the residual data and block dynamicquantization unit 2404 may perform a quantization process that quantizesthe coefficients. Furthermore, in some examples, video encoder 200 maygenerate digital values based on the prediction data. For instance,quantization unit 206 may quantize digital sample values of theprediction data and entropy encoding unit 208 may entropy encode thequantized digital sample values to generate the digital values. Modem108 may be configured to transmit the digital values. For instance,modem 108 may be configured to generate bit sequences based on thedigital values and modulate an analog signal based on the bit sequences.

Additionally, spectral efficiency unit 2406 may determine a spectralefficiency for a channel (2502). Furthermore, packing unit 2408 maydetermine a value n based on the spectral efficiency of the channel anda number of bits in quantized coefficients of the block (2504). Forinstance, packing unit 2408 may look up the value n based on thespectral efficiency of the channel and the number of bits in quantizedcoefficients of the block. In some examples, modem 108 is configured tooutput data indicating the spectral efficiency for the channel. In someexamples, modem 108 is configured to output data indicating the value n.

Additionally, packing unit 2408 may generate coefficient vectors (2506).Each of the coefficient vectors includes n of the coefficients. For eachof the coefficient vectors, packing unit 2408 may determine an amplitudevalue for the coefficient vector based on a mapping pattern. For eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors, the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values. Forexample, packing unit 2408 may determine a position in the n-dimensionalspace. Coordinates of the position in the n-dimensional space are basedon the coefficients of the coefficient vector and the mapping patternmaps different positions in the n-dimensional space to differentamplitude values in the plurality of amplitude values. In this example,packing unit 2408 may determine the amplitude value for the coefficientvector as the amplitude value corresponding to the determined positionin the n-dimensional space.

Source device 102 may modulate an analog signal based on the amplitudevalues for the coefficient vectors (2508). For instance, analogmodulation unit 222 may determine analog symbols based on amplitudevalues and modem 108 may be configured to modulate the analog based onphase shifts and power corresponding to the analog symbols. Modem 108may output the analog signal on the channel (2510).

FIG. 26 is a flowchart illustrating an example method for decoding videodata in accordance with one or more techniques of this disclosure. Inthe example of FIG. 26, modem 122 of destination device 116 (FIG. 1) maybe configured to receive an analog signal that was transmitted via achannel (2600).

Analog demodulation unit 314 (FIG. 3) may demodulate the analog signalto determine amplitude values for a plurality of coefficient vectors(2602). Analog demodulation unit 314 may demodulate the analog signal todetermine the amplitude values as described in any of the examplesprovided elsewhere in this disclosure.

Unpacking unit 316 may determine a value n (2604). The value n is basedon at the spectral efficiency of the channel (e.g., SEi) and a number ofbits in quantized coefficients of the block (e.g., Q_(i)). For instance,unpacking unit 316 may determine the value of n by dividing SE_(i) byQ_(i). In some examples, modem 133 is configured to receive dataindicating the spectral efficiency for the channel.

For each of the coefficient vectors, unpacking unit 316 may determinecoefficients in the coefficient vector based on the amplitude value forthe coefficient vector and a mapping pattern (2606). For each respectiveallowed coefficient vector in a plurality of allowed coefficientvectors, the mapping pattern maps the respective allowed coefficientvector to a respective amplitude value in a plurality of amplitudevalues, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values. Insome examples, as part of determining the coefficients in thecoefficient vector, the unpacking unit 316 may determine thecoefficients in the coefficient vector as coordinates of a position inthe n-dimensional space that corresponds to the amplitude value, whereinthe mapping pattern maps different positions in the n-dimensional spaceto different amplitude values in the plurality of amplitude values.

Furthermore, video decoder 300 may generate the video data based on thecoefficients in the coefficient vectors (2608). In some examples, modem122 may be configured to output digital values based on a receivedsignal. In this example, video decoder 300 may generate prediction databased on the digital values. For instance, entropy decoding unit 304 mayentropy decode the digital values to generate quantized digital samplevalues and dequantization unit 306 may inverse quantize the quantizeddigital sample values to generate the prediction data. Analogdecompression unit 308 may generate a block of digital sample values inresidual data based on the coefficients. For instance, dequantizationunit 318 of analog decompression unit 308 may perform an inversequantization process that inverse quantizes the coefficients andde-binarization unit 320 may perform a de-binarization process thatgenerates the residual data based on the coefficients. Reconstructionunit 310 may generate digital sample values of the video data based onthe residual data and the prediction data. For instance, reconstructionunit 310 may add digital sample values of the residual data tocorresponding digital sample values of the prediction data to generatethe digital sample values of the video data.

Examples in the various aspects of this disclosure may be usedindividually or in any combination.

The following is a non-limiting list of aspects that are in accordancewith one or more techniques of this disclosure.

Aspect 1A. A method of encoding video data, the method comprising:generating coefficients based on the video data; generating coefficientvectors, wherein each of the coefficient vectors includes n of thecoefficients; for each of the coefficient vectors, determining anamplitude value for the coefficient vector based on a mapping pattern,wherein for each respective allowed coefficient vector in a plurality ofallowed coefficient vectors: the mapping pattern maps the respectiveallowed coefficient vector to a respective amplitude value in aplurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values;modulating an analog signal based on the amplitude values for thecoefficient vectors; and outputting the analog signal.

Aspect 2A. The method of aspect 1A, wherein determining the amplitudevalue for the coefficient vector comprises: determining a position inthe n-dimensional space, wherein coordinates of the position in then-dimensional space are based on the coefficients of the coefficientvector, and the mapping pattern maps different positions in then-dimensional space to different amplitude values in the plurality ofamplitude values; and determining the amplitude value for thecoefficient vector as the amplitude value corresponding to thedetermined position in the n-dimensional space.

Aspect 3A. The method of aspects 1A or 2A, wherein the mapping patternmaps unsigned coefficients to an unsigned amplitude value.

Aspect 4A. The method of aspects 1A or 2A, wherein the mapping patternmaps signed coefficients to a signed amplitude value.

Aspect 5A. The method of aspects 1A or 2A, wherein the mapping patternmaps unsigned coefficients to a signed amplitude value.

Aspect 6A. The method of any of aspects 1A-5A, wherein n is greater thanor equal to 2.

Aspect 7A. The method of any of aspects 1A-3A or 5A-6A, wherein:generating the coefficients based on the video data comprises:generating initial coefficients based on the video data; generating signvalues indicating positive/negative signs of the initial coefficients;and generating the coefficients as absolute values of the initialcoefficients, and the method further comprises signaling datarepresenting the sign values.

Aspect 8A. The method of any of aspects 1A-3A or 5A-6A, wherein: thecoefficients are non-negative versions of initial coefficients,generating the coefficients based on the video data comprises:generating the initial coefficients based on the video data; determininga shift value based on a most-negative initial coefficient of theinitial coefficients; and performing a process that transforms theinitial coefficients based on the shift value to the non-negativeversions of the initial coefficients, and the method further comprisessignaling data representing the shift value.

Aspect 9A. The method of any of aspects 1A, 2A, 4A, and 6A-8A, whereinthe coefficient vector includes one or more negative coefficients andone or more positive coefficients.

Aspect 10A. The method of any of aspects 1A-9A, wherein: generating thecoefficients based on the video data comprises: generating predictiondata for the video data; generating residual data based on theprediction data and digital sample values in the video data; andgenerating the coefficients based on the residual data, and the methodfurther comprises: generating digital values based on the predictiondata; and transmitting the digital values.

Aspect 11A. The method of aspect 10A, wherein generating thecoefficients based on the residual data comprises: performing abinarization process that generates the coefficients based on theresidual data; and performing a quantization process that quantizes thecoefficients.

Aspect 12A. The method of aspects 10A or 11A, wherein generating thedigital values based on the prediction data comprises: generatingquantized digital sample values based on digital sample values in theprediction data; and performing an entropy-encoding process thatgenerates the digital values based on the quantized digital samplevalues.

Aspect 13A. A method of decoding video data, the method comprising:determining, based on an analog signal, amplitude values for a pluralityof coefficient vectors; for each of the coefficient vectors, determiningcoefficients in the coefficient vector based on the amplitude value forthe coefficient vector and a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerating the video data based on the coefficients in the coefficientvectors.

Aspect 14A. The method of aspect 13A, wherein determining coefficientsin the coefficient vector based on the amplitude value for thecoefficient vector comprises: determining the coefficients in thecoefficient vector as coordinates of a position in the n-dimensionalspace that corresponds to the amplitude value, wherein the mappingpattern maps different positions in the n-dimensional space to differentamplitude values in the plurality of amplitude values.

Aspect 15A. The method of aspects 13A or 14A, wherein the mappingpattern maps unsigned coefficients to an unsigned amplitude value.

Aspect 16A. The method of aspects 13A or 14A, wherein the mappingpattern maps signed coefficients to a signed amplitude value.

Aspect 17A. The method of aspect 13A or 14A, wherein the mapping patternmaps unsigned coefficients to a signed amplitude value.

Aspect 18A. The method of any of aspects 13A-17A, wherein determiningthe amplitude values for the plurality of coefficient vectors comprises:determining an analog symbol corresponding to a phase shift and a powerfor a symbol sampling instant of the analog signal; and determining theamplitude value for the coefficient vector as one of the coordinates ofthe analog symbol in an I-Q plane.

Aspect 19A. The method of any of aspects 13A-18A, wherein n is greaterthan or equal to 2.

Aspect 20A. The method of any of aspects 13A-15A or 17A-19A, whereindetermining the coefficients in the coefficient vector based on theamplitude value and the mapping pattern comprises: obtaining sign valuesvia a digital path of a modem, wherein the sign values indicatepositive/negative signs of the coefficients in the coefficient vector;determining, based on the amplitude value for the coefficient vector andthe mapping pattern, absolute values of the coefficients in thecoefficient vector; and reconstructing the coefficients in thecoefficient vector at least in part by applying the sign values to theabsolute values of the coefficients in the coefficient vector.

Aspect 21A. The method of any of aspects 13A-15A or 17A-19A, whereindetermining the coefficients in the coefficient vector based on theamplitude value and the mapping pattern comprises: obtaining, via adigital path of a modem, data representing a shift value, wherein theshift value indicates a most-negative coefficient of the coefficients inthe coefficient vector; determining, based on the amplitude value forthe coefficient vector and the mapping pattern, intermediate values ofthe coefficients in the coefficient vector; and reconstructing thecoefficients in the coefficient vector at least in part by adding theshift value to each of the intermediate values of the coefficients inthe coefficient vector.

Aspect 22A. The method of any of aspects 13A, 14A, 16A, or 18A-21A,wherein the coefficient vector includes one or more negativecoefficients and one or more positive coefficients.

Aspect 23A. The method of any of aspects 13A-22A, wherein generating thevideo data based on the coefficients in the coefficient vectorcomprises: obtaining digital values via a digital path of a modem;generating prediction data based on the digital values; generatingresidual data based on the coefficients in the coefficient vectors; andgenerating the video data based on the prediction data and the residualdata.

Aspect 24A. The method of aspect 23A, wherein generating the residualdata based on the coefficients in the coefficient vectors comprises:performing an inverse quantization process that inverse quantizes thecoefficients in the coefficient vectors; and performing ade-binarization process that generates the residual data based on theinverse-quantized coefficients in the coefficient vectors.

Aspect 25A. The method of any of aspects 23A-24A, wherein generating theprediction data based on the digital values comprises: performing anentropy-decoding process that generates the digital sample values basedon the digital values; and generating the prediction data at least inpart by inverse quantizing the digital sample values.

Aspect 26A. A device for encoding video data, the device comprising: oneor more processors implemented in circuitry, the one or more processorsconfigured to: generate coefficients based on video data; generatecoefficient vectors, wherein each of the coefficient vectors includes nof the coefficients; and for each of the coefficient vectors, determinean amplitude value for the coefficient vector based on a mappingpattern, wherein for each respective allowed coefficient vector in aplurality of allowed coefficient vectors: the mapping pattern maps therespective allowed coefficient vector to a respective amplitude value ina plurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; anda modem configured to modulate an analog signal based on the amplitudevalues for the coefficient vectors.

Aspect 27A. The device of aspect 26A, wherein the one or more processorsare configured such that, as part of determining the amplitude value forthe coefficient vector, the one or more processors: determine a positionin the n-dimensional space, wherein coordinates of the position in then-dimensional space are based on the coefficients of the coefficientvector, and the mapping pattern maps different positions in then-dimensional space to different amplitude values in the plurality ofamplitude values; and determine the amplitude value for the coefficientvector as the amplitude value corresponding to the determined positionin the n-dimensional space.

Aspect 28A. The device of aspects 26A or 27A, wherein the mappingpattern maps unsigned coefficients to an unsigned amplitude value.

Aspect 29A. The device of any of aspects 26A-28, wherein the mappingpattern maps signed coefficients to a signed amplitude value.

Aspect 30A. The device of any of aspects 26A-28A, wherein the mappingpattern maps unsigned coefficients to a signed amplitude value.

Aspect 31A. The device of any of aspects 26A-30A, wherein n is greaterthan or equal to 2.

Aspect 32A. The device of any of aspects 26A-28A or 30A-31A, wherein:the one or more processors are configured such that, as part ofgenerating the coefficients based on the residual data, the one or moreprocessors: generate initial coefficients based on the residual data;generate sign values indicating positive/negative signs of the initialcoefficients; and generate the coefficients as absolute values of theinitial coefficients, and the modem is configured to transmit the signvalues via a digital path.

Aspect 33A. The device of any of aspects 26A-28A or 30A-31A, wherein:the coefficients are non-negative versions of initial coefficients, theone or more processors are configured such that, as part of generatingthe coefficients based on the residual data, the one or more processors:generate the initial coefficients based on the residual data; determinea shift value based on a most-negative initial coefficient of theinitial coefficients; and perform a process that transforms the initialcoefficients based on the shift value to the non-negative versions ofthe initial coefficients, and the method further comprises signalingdata representing the shift value.

Aspect 34A. The device of any of aspects 26A-27A, 29A, or 31A-33A,wherein the coefficient vector includes one or more negativecoefficients and one or more positive coefficients.

Aspect 35A. The device of any of aspects 26A-34A, wherein: the one ormore processors are configured such that, as part of generating thecoefficients based on the video data, the one or more processors:generate prediction data for the video data; generate residual databased on the prediction data and digital sample values in the videodata; and generate the coefficients based on the residual data, the oneor more processors are further configured to generate digital valuesbased on the prediction data, and the modem is configured to transmitthe digital values.

Aspect 36A. The device of aspect 35A, wherein the one or more processorsare configured such that, as part of generating the coefficients basedon the residual data, the one or more processors: perform a binarizationprocess that generates the coefficients based on the residual data; andperform a quantization process that quantizes the coefficients.

Aspect 37A. The device of any of aspects 35A-36A, wherein the one ormore processors are configured such that, as part of generating thedigital values based on the prediction data, the one or more processors:generate quantized digital sample values based on digital sample valuesin the prediction data; and perform an entropy-encoding process thatgenerates the digital values based on the quantized digital samplevalues.

Aspect 38A. The device of any of aspects 26A-37A, wherein the devicecomprises one or more of a camera, a computer, a mobile device, abroadcast receiver device, or a set-top box.

Aspect 39A. A device for decoding video data, the device comprising: amodem configured to receive an analog signal; and one or more processorsimplemented in circuitry, the one or more processors configured to:determine, based on the analog signal, amplitude values for a pluralityof coefficient vectors; for each of the coefficient vectors, determinecoefficients in the coefficient vector based on the amplitude value forthe coefficient vector and a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerate video data based on the coefficients in the coefficientvectors.

Aspect 40A. The device of aspect 39A, wherein the one or more processorsare configured such that, as part of determining coefficients in thecoefficient vector based on the amplitude value for the coefficientvector, the one or more processors: determine the coefficients in thecoefficient vector as coordinates of a position in the n-dimensionalspace that corresponds to the amplitude value, wherein the mappingpattern maps different positions in the n-dimensional space to differentamplitude values in the plurality of amplitude values.

Aspect 41A. The device of aspects 39A or 40A, wherein the mappingpattern maps unsigned coefficients to an unsigned amplitude value.

Aspect 42A. The device of aspects 39A or 40A, wherein the mappingpattern maps signed coefficients to a signed amplitude value.

Aspect 43A. The device of aspects 39A or 40A, wherein the mappingpattern maps unsigned coefficients to a signed amplitude value.

Aspect 44A. The device of any of aspects 39A-43A, wherein: the modem isconfigured to determine an analog symbol corresponding to a phase shiftand a power for a symbol sampling instant of the analog signal, andwherein the one or more processors are configured such that, as part ofdetermining the amplitude values for the plurality of coefficientvectors, the one or more processors determine the amplitude value forthe coefficient vector as one of the coordinates of the analog symbol inan I-Q plane.

Aspect 45A. The device of any of aspects 39A-44A, wherein n is greaterthan or equal to 2.

Aspect 46A. The device of any of aspects 39A-41A or 43A-45A, wherein theone or more processors are configured such that, as part of determiningthe coefficients in the coefficient vector based on the amplitude valueand the mapping pattern, the one or more processors: obtain sign valuesvia a digital path of the modem, wherein the sign values indicatepositive/negative signs of the coefficients in the coefficient vector;determine, based on the amplitude value for the coefficient vector andthe mapping pattern, absolute values of the coefficients in thecoefficient vector; and reconstruct the coefficients in the coefficientvector at least in part by applying the sign values to the absolutevalues of the coefficients in the coefficient vector.

Aspect 47A. The device of any of aspects 39A-41A or 43A-45A, wherein theone or more processors are configured such that, as part of determiningthe coefficients in the coefficient vector based on the amplitude valueand the mapping pattern, the one or more processors: obtain, via adigital path of the modem, data representing a shift value, wherein theshift value indicates a most-negative coefficient of the coefficients inthe coefficient vector; determine, based on the amplitude value for thecoefficient vector and the mapping pattern, intermediate values of thecoefficients in the coefficient vector; and reconstruct the coefficientsin the coefficient vector at least in part by adding the shift value toeach of the intermediate values of the coefficients in the coefficientvector.

Aspect 48A. The device of any of aspects 39A-40A, 42A, 44A-47A, whereinthe coefficient vector includes one or more negative coefficients andone or more positive coefficients.

Aspect 49A. The device of any of aspects 39A-48A, wherein the one ormore processors are configured such that, as part of generating thevideo data based on the coefficients in the coefficient vector, the oneor more processors: obtain digital values via a digital path of a modem;generate prediction data based on the digital values; generateprediction data for a current block of the analog video data; generateresidual data based on the coefficients in the coefficient vectors; andgenerate the video data based on the prediction data and the residualdata.

Aspect 50A. The device of aspect 49A, wherein the one or more processorsare configured such that, as part of generating the residual data basedon the coefficients in the coefficient vectors, the one or moreprocessors: perform an inverse quantization process that inversequantizes the coefficients in the coefficient vectors; and perform ade-binarization process that generates the residual data based on theinverse-quantized coefficients in the coefficient vectors.

Aspect 51A. The device of aspects 49A or 50A, wherein the one or moreprocessors are configured such that, as part of generating theprediction data based on the digital values, the one or more processors:perform an entropy-decoding process that generates the digital samplevalues based on the digital values; and generate the prediction data atleast in part by inverse quantizing the digital sample values.

Aspect 52A. The device of any of aspects 39A-51A, wherein the devicecomprises one or more of a camera, a computer, a mobile device, abroadcast receiver device, or a set-top box.

Aspect 53A. A device for encoding video data, the device comprising:means for generating coefficients based on video data; means forgenerating coefficient vectors, wherein each of the coefficient vectorsincludes n of the coefficients; for each of the coefficient vectors,means for determining an amplitude value for the coefficient vectorbased on a mapping pattern, wherein for each respective allowedcoefficient vector in a plurality of allowed coefficient vectors: themapping pattern maps the respective allowed coefficient vector to arespective amplitude value in a plurality of amplitude values, and therespective amplitude value is adjacent in an n-dimensional space to atleast one other amplitude value in the plurality of amplitude valuesthat is adjacent to the respective amplitude value in a monotonic numberline of the amplitude values; and means for modulating an analog signalbased on the amplitude values for the coefficient vectors.

Aspect 54A. A device for decoding video data, the device comprising:means for determining, based on an analog signal, amplitude values for aplurality of coefficient vectors; for each of the coefficient vectors,means for determining coefficients in the coefficient vector based onthe amplitude value for the coefficient vector and a mapping pattern,wherein for each respective allowed coefficient vector in a plurality ofallowed coefficient vectors: the mapping pattern maps the respectiveallowed coefficient vector to a respective amplitude value in aplurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andmeans for generating video data based on the coefficients in thecoefficient vectors.

Aspect 55A. A computer-readable data storage medium having instructionsstored thereon that, when executed, cause one or more processors to:generate coefficients based on video data; generate coefficient vectors,wherein each of the coefficient vectors includes n of the coefficients;for each of the coefficient vectors, determine an amplitude value forthe coefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andmodulate an analog signal based on the amplitude values for thecoefficient vectors.

Aspect 56A. A computer-readable data storage medium having instructionsstored thereon that, when executed, cause one or more processors to:determine, based on an analog signal, amplitude values for a pluralityof coefficient vectors; for each of the coefficient vectors, determinecoefficients in the coefficient vector based on the amplitude value forthe coefficient vector and a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerate video data based on the coefficients in the coefficientvectors.

Aspect 1B. A method of encoding video data, the method comprising:generating coefficients based on digital sample values of the videodata; determining a spectral efficiency for a channel on which to sendan analog signal; determining a value n based on the spectral efficiencyof the channel; generating coefficient vectors, wherein each of thecoefficient vectors includes n of the coefficients; for each of thecoefficient vectors, determining an amplitude value for the coefficientvector based on a mapping pattern, wherein for each respective allowedcoefficient vector in a plurality of allowed coefficient vectors: themapping pattern maps the respective allowed coefficient vector to arespective amplitude value in a plurality of amplitude values, and therespective amplitude value is adjacent in an n-dimensional space to atleast one other amplitude value in the plurality of amplitude valuesthat is adjacent to the respective amplitude value in a monotonic numberline of the amplitude values, and modulating the analog signal based onthe amplitude values for the coefficient vectors; and outputting theanalog signal on the channel.

Aspect 2B. The method of aspect 1B, wherein determining the amplitudevalue for the coefficient vector comprises: determining a position inthe n-dimensional space, wherein coordinates of the position in then-dimensional space are based on the coefficients of the coefficientvector, and the mapping pattern maps different positions in then-dimensional space to different amplitude values in the plurality ofamplitude values; and determining the amplitude value for thecoefficient vector as the amplitude value corresponding to thedetermined position in the n-dimensional space.

Aspect 3B. The method of any of aspects 1B-2B, wherein: generating thecoefficients based on the video data comprises: generating predictiondata for the video data; generating residual data based on theprediction data and digital sample values of the video data; andgenerating the coefficients based on a block of digital sample values inthe residual data, and the method further comprises: generating digitalvalues based on the prediction data; and transmitting the digitalvalues.

Aspect 4B. The method of aspect 3B, wherein generating the coefficientsbased on the video data comprises: performing a binarization processthat generates the coefficients based on the residual data; andperforming a quantization process that quantizes the coefficients.

Aspect 5B. The method of aspect 4B, wherein determining the value ncomprises determining the value n based on the spectral efficiency ofthe channel and a number of bits in quantized coefficients of the block.

Aspect 6B. The method of any of aspects 1B-5B, further comprisingoutputting data indicating the spectral efficiency for the channel.

Aspect 7B. A method of decoding video data, the method comprising:receiving an analog signal that was transmitted via a channel;demodulating the analog signal to determine amplitude values for aplurality of coefficient vectors; determining a value n, wherein thevalue n is based on the spectral efficiency of the channel; for each ofthe coefficient vectors, determining coefficients in the coefficientvector based on the amplitude value for the coefficient vector and amapping pattern, wherein for each respective allowed coefficient vectorin a plurality of allowed coefficient vectors: the mapping pattern mapsthe respective allowed coefficient vector to a respective amplitudevalue in a plurality of amplitude values, and the respective amplitudevalue is adjacent in an n-dimensional space to at least one otheramplitude value in the plurality of amplitude values that is adjacent tothe respective amplitude value in a monotonic number line of theamplitude values; and generating the video data based on thecoefficients in the coefficient vectors.

Aspect 8B. The method of aspect 7B, wherein determining the coefficientsin the coefficient vector comprises: determining the coefficients in thecoefficient vector as coordinates of a position in the n-dimensionalspace that corresponds to the amplitude value, wherein the mappingpattern maps different positions in the n-dimensional space to differentamplitude values in the plurality of amplitude values.

Aspect 9B. The method of aspects 7B or 8B, wherein: the method furthercomprises: receiving digital values; generating prediction data based onthe digital values; and generating the video data based on thecoefficients in the coefficient vectors comprises: generating a block ofdigital sample values in residual data based on the coefficients, andgenerating digital sample values of the video data based on the residualdata and the prediction data.

Aspect 10B. The method of aspect 9B, wherein generating the block ofdigital sample values in the residual data based on the coefficientscomprises: performing an inverse quantization process that inversequantizes the coefficients; and performing a de-binarization processthat generates the residual data based on the coefficients.

Aspect 11B. The method of aspect 10B, wherein the value n is based onthe spectral efficiency of the channel and a number of bits in quantizedcoefficients of the block.

Aspect 12B. The method of any of aspects 7B-11B, further comprisingreceiving data indicating the spectral efficiency for the channel.

Aspect 13B. A device for encoding video data, the device comprising: amemory configured to store the video data; one or more processorsimplemented in circuitry, the one or more processors configured to:generate coefficients based on digital sample values of the video data;determine a spectral efficiency for a channel on which to output ananalog signal; determine a value n based on the spectral efficiency ofthe channel; generate coefficient vectors, wherein each of thecoefficient vectors includes n of the coefficients; for each of thecoefficient vectors, determine an amplitude value for the coefficientvector based on a mapping pattern, wherein for each respective allowedcoefficient vector in a plurality of allowed coefficient vectors: themapping pattern maps the respective allowed coefficient vector to arespective amplitude value in a plurality of amplitude values, and therespective amplitude value is adjacent in an n-dimensional space to atleast one other amplitude value in the plurality of amplitude valuesthat is adjacent to the respective amplitude value in a monotonic numberline of the amplitude values, and modulate the analog signal based onthe amplitude values for the coefficient vectors; and a modem configuredto output the analog signal on the channel.

Aspect 14B. The device of aspect 13B, wherein the one or more processorsare configured such that, as part of determining the amplitude value forthe coefficient vector, the one or more processors: determine a positionin the n-dimensional space, wherein coordinates of the position in then-dimensional space are based on the coefficients of the coefficientvector, and the mapping pattern maps different positions in then-dimensional space to different amplitude values in the plurality ofamplitude values; and determine the amplitude value for the coefficientvector as the amplitude value corresponding to the determined positionin the n-dimensional space.

Aspect 15B. The device of any of aspects 13B-14B, wherein: the one ormore processors are configured such that, as part of generating thecoefficients based on the video data, the one or more processors:generate prediction data for the video data; generate residual databased on the prediction data and digital sample values of the videodata; and generate the coefficients based on a block of digital samplevalues in the residual data, and the one or more processors are furtherconfigured to generate digital values based on the prediction data, andthe modem is configured to transmit the digital values.

Aspect 16B. The device of aspect 15B, wherein the one or more processorsare configured such that, as part of generating the coefficients basedon the video data, the one or more processors: perform a binarizationprocess that generates the coefficients based on the residual data; andperform a quantization process that quantizes the coefficients.

Aspect 17B. The device of aspect 16B, wherein the one or more processorsare configured such that, as part of determining the value n, the one ormore processors determine the value n based on the spectral efficiencyof the channel and a number of bits in quantized coefficients of theblock.

Aspect 18B. The device of any of aspects 13B-17, wherein the modem isfurther configured to output data indicating the spectral efficiency forthe channel.

Aspect 19B. The device of any of aspects 13B-18B, wherein the devicecomprises one or more of a camera, a computer, a mobile device, abroadcast receiver device, or a set-top box.

Aspect 20B. A device for decoding video data, the device comprising: amodem configured to receive an analog signal that was transmitted via achannel; one or more processors implemented in circuitry, the one ormore processors configured to: demodulate the analog signal to determineamplitude values for a plurality of coefficient vectors; determine avalue n, wherein the value n is based on the spectral efficiency of thechannel; for each of the coefficient vectors, determine coefficients inthe coefficient vector based on the amplitude value for the coefficientvector and a mapping pattern, wherein for each respective allowedcoefficient vector in a plurality of allowed coefficient vectors: themapping pattern maps the respective allowed coefficient vector to arespective amplitude value in a plurality of amplitude values, and therespective amplitude value is adjacent in an n-dimensional space to atleast one other amplitude value in the plurality of amplitude valuesthat is adjacent to the respective amplitude value in a monotonic numberline of the amplitude values; generate the video data based on thecoefficients in the coefficient vectors.

Aspect 21B. The device of aspect 20B, wherein the one or more processorsare configured such that, as part of determining the coefficients in thecoefficient vector, the one or more processors: determine thecoefficients in the coefficient vector as coordinates of a position inthe n-dimensional space that corresponds to the amplitude value, whereinthe mapping pattern maps different positions in the n-dimensional spaceto different amplitude values in the plurality of amplitude values.

Aspect 22B. The device of aspects 20B or 21B, wherein: the modem isfurther configured to receive digital values; the one or more processorsare further configured to generate prediction data based on the digitalvalues; and the one or more processors are configured such that, as partof generating the video data based on the coefficients in thecoefficient vectors, the one or more processors: generate a block ofdigital sample values in residual data based on the coefficients, andgenerate digital sample values of the video data based on the residualdata and the prediction data.

Aspect 23B. The device of aspect 22B, wherein the one or more processorsare configured such that, as part of generating the block of digitalsample values in the residual data based on the coefficients, the one ormore processors: perform an inverse quantization process that inversequantizes the coefficients; and perform a de-binarization process thatgenerates the residual data based on the coefficients.

Aspect 24B. The device of aspect 23B, wherein the value n is based onthe spectral efficiency of the channel and a number of bits in quantizedcoefficients of the block.

Aspect 25B. The device of any of aspects 20B-24B, wherein the modem isfurther configured to receive data indicating the spectral efficiencyfor the channel.

Aspect 26B. The device of any of aspects 20B-25B, wherein the devicecomprises one or more of a camera, a computer, a mobile device, abroadcast receiver device, or a set-top box.

Aspect 27B. A device for encoding video data, the device comprising:means for generating coefficients based on digital sample values of thevideo data; means for determining a spectral efficiency for a channel onwhich to output an analog signal; means for determining a value n basedon the spectral efficiency of the channel; means for generatingcoefficient vectors, wherein each of the coefficient vectors includes nof the coefficients; for each of the coefficient vectors, means fordetermining an amplitude value for the coefficient vector based on amapping pattern, wherein for each respective allowed coefficient vectorin a plurality of allowed coefficient vectors: the mapping pattern mapsthe respective allowed coefficient vector to a respective amplitudevalue in a plurality of amplitude values, and the respective amplitudevalue is adjacent in an n-dimensional space to at least one otheramplitude value in the plurality of amplitude values that is adjacent tothe respective amplitude value in a monotonic number line of theamplitude values, and means for modulating the analog signal based onthe amplitude values for the coefficient vectors; and means foroutputting the analog signal on the channel.

Aspect 28B. A device for decoding video data, the device comprising:means for receiving an analog signal that was transmitted via a channel;means for demodulating the analog signal to determine amplitude valuesfor a plurality of coefficient vectors; means for determining a value n,wherein the value n is based on the spectral efficiency of the channel;for each of the coefficient vectors, means for determining coefficientsin the coefficient vector based on the amplitude value for thecoefficient vector and a mapping pattern, wherein for each respectiveallowed coefficient vector in a plurality of allowed coefficientvectors: the mapping pattern maps the respective allowed coefficientvector to a respective amplitude value in a plurality of amplitudevalues, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values;means for generating the video data based on the coefficients in thecoefficient vectors.

Aspect 29B. A computer-readable data storage medium having instructionsstored thereon that, when executed, cause one or more processors to:generate coefficients based on digital sample values of video data;determine a spectral efficiency for a channel on which to output ananalog signal; determine a value n based on the spectral efficiency ofthe channel; generate coefficient vectors, wherein each of thecoefficient vectors includes n of the coefficients; for each of thecoefficient vectors, determine an amplitude value for the coefficientvector based on a mapping pattern, wherein for each respective allowedcoefficient vector in a plurality of allowed coefficient vectors: themapping pattern maps the respective allowed coefficient vector to arespective amplitude value in a plurality of amplitude values, and therespective amplitude value is adjacent in an n-dimensional space to atleast one other amplitude value in the plurality of amplitude valuesthat is adjacent to the respective amplitude value in a monotonic numberline of the amplitude values, and modulate the analog signal based onthe amplitude values for the coefficient vectors; and output the analogsignal on the channel.

Aspect 30B. A computer-readable data storage medium having instructionsstored thereon that, when executed, cause one or more processors to:receive an analog signal that was transmitted via a channel; demodulatethe analog signal to determine amplitude values for a plurality ofcoefficient vectors; determine a value n, wherein the value n is basedon the spectral efficiency of the channel; for each of the coefficientvectors, determine coefficients in the coefficient vector based on theamplitude value for the coefficient vector and a mapping pattern,wherein for each respective allowed coefficient vector in a plurality ofallowed coefficient vectors: the mapping pattern maps the respectiveallowed coefficient vector to a respective amplitude value in aplurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerate video data based on the coefficients in the coefficientvectors.

Aspect 1C. A method of encoding video data, the method comprising:generating prediction data for the video data; generating residual databased on the prediction data and digital sample values of the videodata; generating coefficients based on the residual data; performing aninterlacing process to generate an interlaced amplitude value, whereinthe interlacing process interlaces bits of two or more of thecoefficients to generate the interlaced amplitude value; generatingdigital values based on the prediction data; and outputting one or moreanalog signals modulated based on the interlaced amplitude value and thedigital values.

Aspect 2C. The method of aspect 1C, wherein: the method furthercomprises performing a mapping process that maps the interlacedamplitude value from an original number line to a mapped value in analternate number line that includes one or more gap ranges, wherein thegap ranges are located at positions in the original number linecorrelated with impacts of noise in terms of bit flips in interlacedamplitude values demodulated from analog signals, and the mappingprocess does not map any interlaced amplitude value to any value in anyof the one or more gap ranges, and outputting the one or more analogsignals comprises modulating an analog signal based on the mapped value.

Aspect 3C. The method of aspects 1C or 2C, wherein the interlacingprocess interlaces the bits of two or four of the coefficients.

Aspect 4C. The method of any of aspects 1C-3C, wherein generating thecoefficients based on the residual data comprises: performing abinarization process that generates the coefficients based on theresidual data; and performing a quantization process that quantizes thecoefficients.

Aspect 5C. The method of any of aspects 1C-4C, wherein generating thedigital values based on the prediction data comprises: generatingquantized digital sample values based on digital sample values in theprediction data; and performing an entropy-encoding process thatgenerates the digital values based on the quantized digital samplevalues.

Aspect 6C. The method of any of aspects 1C-5C, further comprisingselecting, based on a spectral efficiency of a channel through which theanalog signal is transmitted, the interlacing process from a pluralityof interlacing processes.

Aspect 7C. The method of aspect 6C, wherein each of the interlacingprocesses interlaces a different number of the coefficients.

Aspect 8C. A method of decoding video data, the method comprising:determining an interlaced amplitude value based on an analog signal;performing a deinterlacing process to generate two or more coefficients,wherein bits of the two or more coefficients are interlaced in theinterlaced amplitude value; generating residual data based on the two ormore coefficients; obtaining digital values; generating prediction databased on the digital values; and reconstructing the video data based onthe prediction data and the residual data.

Aspect 9C. The method of aspect 8C, wherein determining the interlacedamplitude value based on the analog signal comprises: demodulating theanalog signal to determine a mapped value generated using a mappingprocess that maps interlaced amplitude values in an original number lineto mapped values in an alternate number line that includes one or moregap ranges, wherein the gap ranges are located at positions in theoriginal number line correlated with impacts of noise in terms of bitflips in interlaced amplitude values demodulated from analog signals andthe mapping process does not map any of the interlaced amplitude valuesto any value in any of the one or more gap ranges; and using an inverseof the mapping process to map the mapped value to the interlacedamplitude value.

Aspect 10C. The method of aspects 9C, wherein: the mapped valuedetermined by demodulating the analog signal is in one of the gapranges, and the inverse of the mapping process maps mapped values in thegap ranges to values in the original number line.

Aspect 11C. The method of any of aspects 8C-10C, wherein thedeinterlacing process deinterlaces the bits of two or four of thecoefficients.

Aspect 12C. The method of any of aspects 8C-11C, wherein determining theinterlaced amplitude value based on the analog signal comprises:determining an analog symbol corresponding to a phase shift and powerfor a symbol sampling instant of the analog signal, wherein theinterlaced amplitude value is equal to a coordinate of the analog symbolin an I-Q plane.

Aspect 13C. The method of any of aspects 8C-12C, wherein generating theresidual data based on the coefficients comprises: performing an inversequantization process that inverse quantizes the coefficients; andperforming a de-binarization process that generates the residual databased on the coefficients.

Aspect 14C. The method of any of aspects 8C-13C, wherein generating theprediction data based on the digital values comprises: performing anentropy-decoding process that generates quantized digital sample valuesbased on the digital values; and performing an inverse quantizationprocess that generates digital sample values in the prediction databased on the inverse quantized digital sample values.

Aspect 15C. The method of any of aspects 8C-13C, further comprisingselecting, based on a spectral efficiency of a channel through which theanalog signal is transmitted, the deinterlacing process from a pluralityof deinterlacing processes.

Aspect 16C. The method of aspect 15C, wherein each of the deinterlacingprocesses deinterlaces a different number of the coefficients.

Aspect 17C. A device for encoding video data, the device comprising: amemory configured to store the video data, one or more processorsimplemented in circuitry, the one or more processors configured to:generate prediction data for the video data; generate residual databased on the prediction data and digital sample values of the videodata; generate coefficients based on the residual data; perform aninterlacing process to generate an interlaced amplitude value, whereinthe interlacing process interlaces bits of two or more of thecoefficients to generate the interlaced amplitude value; and generatedigital values based on the prediction data; and a modem configured tooutput one or more analog signals modulated based on the interlacedamplitude value and the digital values.

Aspect 18C. The device of aspect 17C, wherein: the one or moreprocessors are further configured to perform a mapping process that mapsthe interlaced amplitude value from an original number line to a mappedvalue in an alternate number line that includes one or more gap ranges,wherein the gap ranges are located at positions in the original numberline correlated with impacts of noise in terms of bit flips ininterlaced amplitude values demodulated from analog signals, and themapping process does not map any interlaced amplitude value to any valuein any of the one or more gap ranges, and the one or more processors areconfigured such that, as part of outputting the one or more analogsignals, the modem modulates an analog signal based on the mapped value.

Aspect 19C. The device of aspects 17C or 18C, wherein the interlacingprocess interlaces the bits of two or four of the coefficients.

Aspect 20C. The device of any of aspects 17C-19C, wherein the one ormore processors are configured such that, as part of generating thecoefficients based on the residual data, the one or more processors:perform a binarization process that generates the coefficients based onthe residual data; and perform a quantization process that quantizes thecoefficients.

Aspect 21C. The device of any of aspects 17C-20C, wherein the one ormore processors are configured such that, as part of generating thedigital values based on the prediction data, the one or more processors:generate quantized digital sample values based on digital sample valuesin the prediction data; and perform an entropy-encoding process thatgenerates the digital values based on the quantized digital samplevalues.

Aspect 22C. The device of any of aspects 17C-21C, wherein the one ormore processors are further configured to select, based on a spectralefficiency of a channel through which the analog signal is transmitted,the interlacing process from a plurality of interlacing processes.

Aspect 23C. The device of aspect 22C, wherein each of the interlacingprocesses interlaces a different number of the coefficients.

Aspect 24C. The device of any of aspects 17C-23C, wherein the devicecomprises one or more of a camera, a computer, a mobile device, abroadcast receiver device, or a set-top box.

Aspect 25C. A device for decoding video data, the device comprising: amodem configured to obtain an analog signal and digital values; and oneor more processors implemented in circuitry, the one or more processorsconfigured to: determine an interlaced amplitude value based on ananalog signal; perform a deinterlacing process to generate two or morecoefficients, wherein bits of the two or more coefficients areinterlaced in the interlaced amplitude value; generate residual databased on the two or more coefficients; obtain digital values; generateprediction data based on the digital values; and reconstruct the videodata based on the prediction data and the residual data.

Aspect 26C. The device of aspect 25C, wherein the one or more processorsare configured such that, as part of determining the interlacedamplitude value based on the analog signal, the one or more processors:demodulate the analog signal to determine a mapped value generated usinga mapping process that maps interlaced amplitude values in an originalnumber line to mapped values in an alternate number line that includesone or more gap ranges, wherein the gap ranges are located at positionsin the original number line correlated with impacts of noise in terms ofbit flips in interlaced amplitude values demodulated from analog signalsand the mapping process does not map any of the interlaced amplitudevalues to any value in any of the one or more gap ranges; and use aninverse of the mapping process to map the mapped value to the interlacedamplitude value.

Aspect 27C. The device of aspect 26C, wherein: the mapped valuedetermined by demodulating the analog signal is in one of the gapranges, and the inverse of the mapping process maps mapped values in thegap ranges to values in the original number line.

Aspect 28C. The device of any of aspects 25C-27C, wherein thedeinterlacing process deinterlaces the bits of two or four of thecoefficients.

Aspect 29C. The device of any of aspects 25C-28C, wherein the one ormore processors are configured such that, as part of determining theinterlaced amplitude value based on the analog signal, the one or moreprocessors: determine an analog symbol corresponding to a phase shiftand power for a symbol sampling instant of the analog signal, whereinthe interlaced amplitude value is equal to a coordinate of the analogsymbol in an I-Q plane.

Aspect 30C. The device of any of aspects 25C-29C, wherein the one ormore processors are configured such that, as part of generating theresidual data based on the coefficients, the one or more processors:perform an inverse quantization process that inverse quantizes thecoefficients; and perform a de-binarization process that generates theresidual data based on the coefficients.

Aspect 31C. The device of any of aspects 25C-30C, wherein the one ormore processors are configured such that, as part of generating theprediction data based on the digital values, the one or more processors:perform an entropy-decoding process that generates quantized digitalsample values based on the digital values; and perform an inversequantization process that generates digital sample values in theprediction data based on the inverse quantized digital sample values.

Aspect 32C. The device of aspect 31C, wherein the one or more processorsare further configured to select, based on a spectral efficiency of achannel through which the analog signal is transmitted, thedeinterlacing process from a plurality of deinterlacing processes.

Aspect 33C. The device of aspect 32C, wherein each of the deinterlacingprocesses deinterlaces a different number of the coefficients.

Aspect 34C. The device of any of aspects 27C-33C, wherein the devicecomprises one or more of a camera, a computer, a mobile device, abroadcast receiver device, or a set-top box.

Aspect 35C. A device for encoding video data, the device comprising:means for generating prediction data for the video data; means forgenerating residual data based on the prediction data and digital samplevalues of the video data; means for generating coefficients based on theresidual data; means for performing an interlacing process to generatean interlaced amplitude value, wherein the interlacing processinterlaces bits of two or more of the coefficients to generate theinterlaced amplitude value; and means for modulating an analog signalbased on the interlaced amplitude value; means for generating digitalvalues based on the prediction data; and means for outputting the analogsignal and digital values based on the prediction block.

Aspect 36C. A device for decoding video data, the device comprising:means for determining an interlaced amplitude value based on an analogsignal; means for performing a deinterlacing process to generate two ormore coefficients, wherein bits of the two or more coefficients areinterlaced in the interlaced amplitude value; means for generatingresidual data based on the two or more coefficients; means for obtainingdigital values; means for generating prediction data based on thedigital values; and means for reconstructing the video data based on theprediction data and the residual data.

Aspect 37C. A computer-readable data storage medium having instructionsstored thereon that, when executed, cause one or more processors to:generate prediction data for video data; generate residual data based onthe prediction data and digital sample values of the video data;generate coefficients based on the residual data; perform an interlacingprocess to generate an interlaced amplitude value, wherein theinterlacing process interlaces bits of two or more of the coefficientsto generate the interlaced amplitude value; and modulate an analogsignal based on the interlaced amplitude value; generate digital valuesbased on the prediction data; and output the analog signal and digitalvalues based on the prediction block.

Aspect 38C. A computer-readable data storage medium having instructionsstored thereon that, when executed, cause one or more processors to:determine an interlaced amplitude value based on an analog signal;perform a deinterlacing process to generate two or more coefficients,wherein bits of the two or more coefficients are interlaced in theinterlaced amplitude value; generate residual data based on the two ormore coefficients; obtain digital values; generate prediction data basedon the digital values; and reconstruct video data based on theprediction data and the residual data.

It is to be recognized that depending on the example, certain acts orevents of any of the techniques described herein can be performed in adifferent sequence, may be added, merged, or left out altogether (e.g.,not all described acts or events are necessary for the practice of thetechniques). Moreover, in certain examples, acts or events may beperformed concurrently, e.g., through multi-threaded processing,interrupt processing, or multiple processors, rather than sequentially.

In one or more examples, the functions described may be implemented inhardware, software, firmware, or any combination thereof. If implementedin software, the functions may be stored on or transmitted over as oneor more instructions or code on a computer-readable medium and executedby a hardware-based processing unit. Computer-readable media may includecomputer-readable storage media, which corresponds to a tangible mediumsuch as data storage media, or communication media including any mediumthat facilitates transfer of a computer program from one place toanother, e.g., according to a communication protocol. In this manner,computer-readable media generally may correspond to (1) tangiblecomputer-readable storage media which is non-transitory or (2) acommunication medium such as a signal or carrier wave. Data storagemedia may be any available media that can be accessed by one or morecomputers or one or more processors to retrieve instructions, codeand/or data structures for implementation of the techniques described inthis disclosure. A computer program product may include acomputer-readable medium.

By way of example, and not limitation, such computer-readable storagemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage, or other magnetic storage devices, flashmemory, or any other medium that can be used to store desired programcode in the form of instructions or data structures and that can beaccessed by a computer. Also, any connection is properly termed acomputer-readable medium. For example, if instructions are transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, digital subscriber line (DSL), orwireless technologies such as infrared, radio, and microwave, then thecoaxial cable, fiber optic cable, twisted pair, DSL, or wirelesstechnologies such as infrared, radio, and microwave are included in thedefinition of medium. It should be understood, however, thatcomputer-readable storage media and data storage media do not includeconnections, carrier waves, signals, or other transitory media, but areinstead directed to non-transitory, tangible storage media. Disk anddisc, as used herein, includes compact disc (CD), laser disc, opticaldisc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wheredisks usually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above should also be includedwithin the scope of computer-readable media.

Instructions may be executed by one or more processors (e.g.,programmable processors), such as one or more digital signal processors(DSPs), general purpose microprocessors, application specific integratedcircuits (ASICs), field programmable gate arrays (FPGAs), or otherequivalent integrated or discrete logic circuitry. Accordingly, theterms “processor” and “processing circuitry,” as used herein may referto any of the foregoing structures or any other structure suitable forimplementation of the techniques described herein. In addition, in someaspects, the functionality described herein may be provided withindedicated hardware and/or software modules configured for encoding anddecoding, or incorporated in a combined codec. Also, the techniquescould be fully implemented in one or more circuits or logic elements.

The techniques of this disclosure may be implemented in a wide varietyof devices or apparatuses, including a wireless handset, an integratedcircuit (IC) or a set of ICs (e.g., a chip set). Various components,modules, or units are described in this disclosure to emphasizefunctional aspects of devices configured to perform the disclosedtechniques, but do not necessarily require realization by differenthardware units. Rather, as described above, various units may becombined in a codec hardware unit or provided by a collection ofinteroperative hardware units, including one or more processors asdescribed above, in conjunction with suitable software and/or firmware.

Various examples have been described. These and other examples arewithin the scope of the following claims.

What is claimed is:
 1. A method of encoding video data, the methodcomprising: generating coefficients based on digital sample values ofthe video data; determining a spectral efficiency for a channel on whichto send an analog signal; determining a value n based on the spectralefficiency of the channel; generating coefficient vectors, wherein eachof the coefficient vectors includes n of the coefficients; for each ofthe coefficient vectors, determining an amplitude value for thecoefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values, andmodulating the analog signal based on the amplitude values for thecoefficient vectors; and outputting the analog signal on the channel. 2.The method of claim 1, wherein determining the amplitude value for thecoefficient vector comprises: determining a position in then-dimensional space, wherein coordinates of the position in then-dimensional space are based on the coefficients of the coefficientvector, and the mapping pattern maps different positions in then-dimensional space to different amplitude values in the plurality ofamplitude values; and determining the amplitude value for thecoefficient vector as the amplitude value corresponding to thedetermined position in the n-dimensional space.
 3. The method of claim1, wherein: generating the coefficients based on the video datacomprises: generating prediction data for the video data; generatingresidual data based on the prediction data and digital sample values ofthe video data; and generating the coefficients based on a block ofdigital sample values in the residual data, and the method furthercomprises: generating digital values based on the prediction data; andtransmitting the digital values.
 4. The method of claim 3, whereingenerating the coefficients based on the video data comprises:performing a binarization process that generates the coefficients basedon the residual data; and performing a quantization process thatquantizes the coefficients.
 5. The method of claim 4, whereindetermining the value n comprises determining the value n based on thespectral efficiency of the channel and a number of bits in quantizedcoefficients of the block.
 6. The method of claim 1, further comprisingoutputting data indicating the spectral efficiency for the channel.
 7. Amethod of decoding video data, the method comprising: receiving ananalog signal that was transmitted via a channel; demodulating theanalog signal to determine amplitude values for a plurality ofcoefficient vectors; determining a value n, wherein the value n is basedon the spectral efficiency of the channel; for each of the coefficientvectors, determining coefficients in the coefficient vector based on theamplitude value for the coefficient vector and a mapping pattern,wherein for each respective allowed coefficient vector in a plurality ofallowed coefficient vectors: the mapping pattern maps the respectiveallowed coefficient vector to a respective amplitude value in aplurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerating the video data based on the coefficients in the coefficientvectors.
 8. The method of claim 7, wherein determining the coefficientsin the coefficient vector comprises: determining the coefficients in thecoefficient vector as coordinates of a position in the n-dimensionalspace that corresponds to the amplitude value, wherein the mappingpattern maps different positions in the n-dimensional space to differentamplitude values in the plurality of amplitude values.
 9. The method ofclaim 7, wherein: the method further comprises: receiving digitalvalues; generating prediction data based on the digital values; andgenerating the video data based on the coefficients in the coefficientvectors comprises: generating a block of digital sample values inresidual data based on the coefficients, and generating digital samplevalues of the video data based on the residual data and the predictiondata.
 10. The method of claim 9, wherein generating the block of digitalsample values in the residual data based on the coefficients comprises:performing an inverse quantization process that inverse quantizes thecoefficients; and performing a de-binarization process that generatesthe residual data based on the coefficients.
 11. The method of claim 10,wherein the value n is based on the spectral efficiency of the channeland a number of bits in quantized coefficients of the block.
 12. Themethod of claim 7, further comprising receiving data indicating thespectral efficiency for the channel.
 13. A device for encoding videodata, the device comprising: a memory configured to store the videodata; one or more processors implemented in circuitry, the one or moreprocessors configured to: generate coefficients based on digital samplevalues of the video data; determine a spectral efficiency for a channelon which to output an analog signal; determine a value n based on thespectral efficiency of the channel; generate coefficient vectors,wherein each of the coefficient vectors includes n of the coefficients;for each of the coefficient vectors, determine an amplitude value forthe coefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values, andmodulate the analog signal based on the amplitude values for thecoefficient vectors; and a modem configured to output the analog signalon the channel.
 14. The device of claim 13, wherein the one or moreprocessors are configured such that, as part of determining theamplitude value for the coefficient vector, the one or more processors:determine a position in the n-dimensional space, wherein coordinates ofthe position in the n-dimensional space are based on the coefficients ofthe coefficient vector, and the mapping pattern maps different positionsin the n-dimensional space to different amplitude values in theplurality of amplitude values; and determine the amplitude value for thecoefficient vector as the amplitude value corresponding to thedetermined position in the n-dimensional space.
 15. The device of claim13, wherein: the one or more processors are configured such that, aspart of generating the coefficients based on the video data, the one ormore processors: generate prediction data for the video data; generateresidual data based on the prediction data and digital sample values ofthe video data; and generate the coefficients based on a block ofdigital sample values in the residual data, and the one or moreprocessors are further configured to generate digital values based onthe prediction data, and the modem is configured to transmit the digitalvalues.
 16. The device of claim 15, wherein the one or more processorsare configured such that, as part of generating the coefficients basedon the video data, the one or more processors: perform a binarizationprocess that generates the coefficients based on the residual data; andperform a quantization process that quantizes the coefficients.
 17. Thedevice of claim 16, wherein the one or more processors are configuredsuch that, as part of determining the value n, the one or moreprocessors determine the value n based on the spectral efficiency of thechannel and a number of bits in quantized coefficients of the block. 18.The device of claim 13, wherein the modem is further configured tooutput data indicating the spectral efficiency for the channel.
 19. Thedevice of claim 13, wherein the device comprises one or more of acamera, a computer, a mobile device, a broadcast receiver device, or aset-top box.
 20. A device for decoding video data, the devicecomprising: a modem configured to receive an analog signal that wastransmitted via a channel; one or more processors implemented incircuitry, the one or more processors configured to: demodulate theanalog signal to determine amplitude values for a plurality ofcoefficient vectors; determine a value n, wherein the value n is basedon the spectral efficiency of the channel; for each of the coefficientvectors, determine coefficients in the coefficient vector based on theamplitude value for the coefficient vector and a mapping pattern,wherein for each respective allowed coefficient vector in a plurality ofallowed coefficient vectors: the mapping pattern maps the respectiveallowed coefficient vector to a respective amplitude value in aplurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andgenerate the video data based on the coefficients in the coefficientvectors.
 21. The device of claim 20, wherein the one or more processorsare configured such that, as part of determining the coefficients in thecoefficient vector, the one or more processors: determine thecoefficients in the coefficient vector as coordinates of a position inthe n-dimensional space that corresponds to the amplitude value, whereinthe mapping pattern maps different positions in the n-dimensional spaceto different amplitude values in the plurality of amplitude values. 22.The device of claim 20, wherein: the modem is further configured toreceive digital values; the one or more processors are furtherconfigured to generate prediction data based on the digital values; andthe one or more processors are configured such that, as part ofgenerating the video data based on the coefficients in the coefficientvectors, the one or more processors: generate a block of digital samplevalues in residual data based on the coefficients, and generate digitalsample values of the video data based on the residual data and theprediction data.
 23. The device of claim 22, wherein the one or moreprocessors are configured such that, as part of generating the block ofdigital sample values in the residual data based on the coefficients,the one or more processors: perform an inverse quantization process thatinverse quantizes the coefficients; and perform a de-binarizationprocess that generates the residual data based on the coefficients. 24.The device of claim 23, wherein the value n is based on the spectralefficiency of the channel and a number of bits in quantized coefficientsof the block.
 25. The device of claim 20, wherein the modem is furtherconfigured to receive data indicating the spectral efficiency for thechannel.
 26. The device of claim 20, wherein the device comprises one ormore of a camera, a computer, a mobile device, a broadcast receiverdevice, or a set-top box.
 27. A device for encoding video data, thedevice comprising: means for generating coefficients based on digitalsample values of the video data; means for determining a spectralefficiency for a channel on which to output an analog signal; means fordetermining a value n based on the spectral efficiency of the channel;means for generating coefficient vectors, wherein each of thecoefficient vectors includes n of the coefficients; for each of thecoefficient vectors, means for determining an amplitude value for thecoefficient vector based on a mapping pattern, wherein for eachrespective allowed coefficient vector in a plurality of allowedcoefficient vectors: the mapping pattern maps the respective allowedcoefficient vector to a respective amplitude value in a plurality ofamplitude values, and the respective amplitude value is adjacent in ann-dimensional space to at least one other amplitude value in theplurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values, andmeans for modulating the analog signal based on the amplitude values forthe coefficient vectors; and means for outputting the analog signal onthe channel.
 28. A device for decoding video data, the devicecomprising: means for receiving an analog signal that was transmittedvia a channel; means for demodulating the analog signal to determineamplitude values for a plurality of coefficient vectors; means fordetermining a value n, wherein the value n is based on the spectralefficiency of the channel; for each of the coefficient vectors, meansfor determining coefficients in the coefficient vector based on theamplitude value for the coefficient vector and a mapping pattern,wherein for each respective allowed coefficient vector in a plurality ofallowed coefficient vectors: the mapping pattern maps the respectiveallowed coefficient vector to a respective amplitude value in aplurality of amplitude values, and the respective amplitude value isadjacent in an n-dimensional space to at least one other amplitude valuein the plurality of amplitude values that is adjacent to the respectiveamplitude value in a monotonic number line of the amplitude values; andmeans for generating the video data based on the coefficients in thecoefficient vectors.
 29. A computer-readable data storage medium havinginstructions stored thereon that, when executed, cause one or moreprocessors to: generate coefficients based on digital sample values ofvideo data; determine a spectral efficiency for a channel on which tooutput an analog signal; determine a value n based on the spectralefficiency of the channel; generate coefficient vectors, wherein each ofthe coefficient vectors includes n of the coefficients; for each of thecoefficient vectors, determine an amplitude value for the coefficientvector based on a mapping pattern, wherein for each respective allowedcoefficient vector in a plurality of allowed coefficient vectors: themapping pattern maps the respective allowed coefficient vector to arespective amplitude value in a plurality of amplitude values, and therespective amplitude value is adjacent in an n-dimensional space to atleast one other amplitude value in the plurality of amplitude valuesthat is adjacent to the respective amplitude value in a monotonic numberline of the amplitude values, and modulate the analog signal based onthe amplitude values for the coefficient vectors; and output the analogsignal on the channel.
 30. A computer-readable data storage mediumhaving instructions stored thereon that, when executed, cause one ormore processors to: receive an analog signal that was transmitted via achannel; demodulate the analog signal to determine amplitude values fora plurality of coefficient vectors; determine a value n, wherein thevalue n is based on the spectral efficiency of the channel; for each ofthe coefficient vectors, determine coefficients in the coefficientvector based on the amplitude value for the coefficient vector and amapping pattern, wherein for each respective allowed coefficient vectorin a plurality of allowed coefficient vectors: the mapping pattern mapsthe respective allowed coefficient vector to a respective amplitudevalue in a plurality of amplitude values, and the respective amplitudevalue is adjacent in an n-dimensional space to at least one otheramplitude value in the plurality of amplitude values that is adjacent tothe respective amplitude value in a monotonic number line of theamplitude values; and generate video data based on the coefficients inthe coefficient vectors.